SO who came up with the GMC V6's???

[TJ's GMC]

I've been deep into research on these v6's and wondering....what made GM come up with such a different engine? I mean...the thing makes a SBC look like a briggs and stratton. lol And its slower than a 292 I6 by far, but sure has a ton more lugging power. Mine pulls pretty darn good with the 4 barrel and split exhaust, but my 292 with the same mods pulled 10 times faster which makes me wonder....did GM purposely make these to be luggers? Shifting my 292 at 4000 RPM was no problem, but 3000 on this is scary. haha I'm NOT downing the V6's in Any way....just curious as to the engineering behind it. I mean....loaded down with manure I could pull hills at 55 with my 305 no problem and that was with a plugged up 2 barrel. Just thought it would be an interesting discussion. I love my BB V6 and wouldn't trade it for any SBC, but the thing interests me. lol

[George Bongert]

Greetings TJ!

As to who at GM came up with the design of the big block V-6, well, that's information that I don't have, although I also would like to know who that person was. As to the comparison between the 292 I-6 and the various versions of the GMC Big Block V-6's, I'll take the Big Block V-6's any day of the week before I would take the 292 I-6. As many here know, I once owned a 1963 Chevy 30 Series (1 ton) pickup originally equipped with the 292 I-6 which I eventually replaced with a GMC 305 V-6. Now, there will be those here who will disagree with me, but my feeling is that the 292 I-6 was nothing more than a glorified car engine put in a truck, and not necessarily designed to be a truck engine, although GM engineers would differ with me on that point. I know, because my Dad and I had plenty of problems with the 292. When I replaced the 292 with the GMC 305 V-6, those problems all disappeared. Now, having said that, yes, the 292 would be faster on acceleration and rev higher than a BB V-6, but as you indicated, the GMC V-6 will outlug the 292 six ways from Sunday, and all in all is a much more durable engine than the 292 ever was or will ever be. I know you have several 292's in your collection, and that you are very pleased with them. My experience has been the 292 is an engine (along with a few other GM engines) that I do not strongly favor.

On a lighter note, Merry Christmas to all here in the 6066 GMC Truck Club!

[TJ's GMC]

Greetings TJ!

As to who at GM came up with the design of the big block V-6, well, that's information that I don't have, although I also would like to know who that person was. As to the comparison between the 292 I-6 and the various versions of the GMC Big Block V-6's, I'll take the Big Block V-6's any day of the week before I would take the 292 I-6. As many here know, I once owned a 1963 Chevy 30 Series (1 ton) pickup originally equipped with the 292 I-6 which I eventually replaced with a GMC 305 V-6. Now, there will be those here who will disagree with me, but my feeling is that the 292 I-6 was nothing more than a glorified car engine put in a truck, and not necessarily designed to be a truck engine, although GM engineers would differ with me on that point. I know, because my Dad and I had plenty of problems with the 292. When I replaced the 292 with the GMC 305 V-6, those problems all disappeared. Now, having said that, yes, the 292 would be faster on acceleration and rev higher than a BB V-6, but as you indicated, the GMC V-6 will outlug the 292 six ways from Sunday, and all in all is a much more durable engine than the 292 ever was or will ever be. I know you have several 292's in your collection, and that you are very pleased with them. My experience has been the 292 is an engine (along with a few other GM engines) that I do not strongly favor.

On a lighter note, Merry Christmas to all here in the 6066 GMC Truck Club!

Thanks for the reply! SO what problems did you have with the 292? The stock 292 that was in my C10 performed nicely even when towing, but I have now gone through and hotrodded it. lol So it doesn't count as a comparison anymore. But yes, I'm pleased with my 292's. But when I came across my GMC with the V6 I was even More pleased because I never had seen one in person before so I had to have it. lol I Love my V6 and like I mentioned...wouldn't trade it for a SBC or anything for that matter accept a bigger V6. But I'm interested to know what you didn't like about the 292's? GM engineers made the 230's and 250's to be more of a car engine and the 292 to be the truck engine of the bunch(not trying to start an argument). The 292 was made the truck engine because of how much taller the deck height was and the much longer stroke to get that added torque which for my experience in a light duty truck served nicely. But in a large C30 like you had that may have been a different story, but I can easily understand why you'd prefer the V6....they were made so bullet proof and durable its crazy. lol Merry Christmas to you to!

[GMCNUT]

So GMC was married to GM sister division Pontiac in the 40's and 50's and shared Pontiac's design team for engines. GMC used Pontiac car V8's from 55-57 before Pontiac designed GMC its own variation of the 1958 Pontiac 370 V8 which was a smaller bore 336 V8. In 1959 when Pontiac went to the famous 389 V8, they gave GMC another version of the 336 V8 which had a shorter stroke and was based on the 389 V8's bottom end. This version of the 336 was slightly faster in terms of horsepower over the previous years' 336. During these years, Pontiac engineers developed the V6 as a means of giving GMC its own engine that would give the trucks a distinction from Chevrolet and give them the powerful low end torque they are known today for. You can see the Pontiac engineering influence in the power steering pump and fuel pump designs and the way the V6 intake still sits up on top, separated from the push rod valley vs a Chevrolet fully enclosed design. Everything about the GMC V6 design and appearance screams Pontiac when you compare to the early V8's Pontiac shared with GMC. The V6's are the last stand from Pontiac before GM fully aligned GMC with Chevrolet by say 1966 or so and started offering Chevrolet engines in GMC's. By 1969, the V6 was over with, and the Chevrolet V8 won out over the V6 for cost and efficiency reasons and maybe other things like fuel economy. Not sure if this answers your question any but I believe this to be correct unless Pete, Ed or some of the more knowlegeable and experienced V6 users have anything to add that might shed any more light on the subject of who came up with the V6 design

[bigblockv6]

TJ, speaking of acceleration was there a noticeable improvement when you added the 4bbl? One of the drawbacks of the 305 is it has a poor power to weight ratio that's why I prefer the larger displacement V6's. The 305 shares the same block as the rest of the family of 60 degree V6 engines up to the 478, so that makes it really heavy for it's smaller displacement. If you would like to know more on the development of these engines go to Jolly's 6066 GMCguy website and check out the Sept 1959 issue of Popular Science. They actually tested a 1bbl 305 in a prototype 1959 Suburban, being that it was in a smaller and lighter truck the performance was more V8 like of that era.:thumbsup:

[bigblockv6]

GMCNUT, for the most you are correct except for a few things. GMC was not married to Pontiac in the 40's & 50's nor did Pontiac engineers design the GMC V6. In the 50's since GMC didn't have their own V8 they chose the Pontiac V8 and of course the was an excellent choice since Pontiac had larger displacement engines, but the Pontiac V8 wasn't the only V8 GMC offered. Trucks that were larger than medium duty used Oldsmobile V8's because of their low end torque. With the introduction of the V6 that was GMC's remedy to be self sufficient by having their own powerplant, As bigger V8's came around the 305 definitely didn't cut it so the 351 was brought out in the light duty line in 1966, an improvement but demand was there for high horsepower V8's so in 67 they brought out the entire line of Chevrolet engines. That was GMC's downfall as it got much easier to produce trucks that were fully interchangeable with Chevrolet, too bad GMC didn't stick with the Pontiac V8's, It wasn't until around the mid 90's that GMC and Pontiac combined to be the same division and that lasted till 2010 when GM killed off Pontiac.

[George Bongert]

Greetings again TJ, and everyone else in the Club!

As to why I disfavor the 292 I-6, I'll try to be as brief as possible. My Dad bought that '63 Chevy C-30 in 1966 with 42,000 miles on the odometer, and at that time with three new pistons in the engine. After putting on another 3,000 miles, he came home with the engine knocking like crazy. This was in 1968, and I was in high school at the time, taking an auto mechanics course, and I diagnosed the problem (correctly I might add) as being a rod bearing knock. We dropped the oil pan, and it didn't take long to determine that the # 1 rod bearing was totally pounded out. We ordered a new (not rebuilt) short block from our local Chevy dealer, and installed it in an unheated garage in 20 degree below zero weather. Now let me tell you that you only worked on it for about 15 minutes at a time, and then had to go in and get warmed up before continuing to work on it on and off until it was completed. Now, as to problems with the new short block, the engine ran pretty much quietly except for the fact as more miles were racked up, and by the time there was 10,000 miles on that new block, that 292 developed a serious case of piston slap. Remember me mentioning earlier that the original engine had 3 new pistons in it when my dad bought the truck with 42,000 miles on it? It didn't matter whether the engine was cold, or at operating temperature, you could hear every piston in that engine slapping merrily away. Dad turned the truck over to me, and when there was about 70,000 miles on that 292 replacement engine, I knew at some point the dam* thing was going to leave me stranded high and dry somewhere. A neighbor had a 1962 GMC 3/4 ton pickup that he had retired mostly due to the body being pretty rusty. I bought that truck and took the 305 BB V-6 out of it and put it in my '63 Chevy. Putting that BB V-6 in my truck was the best decision I ever made, because it was an engine that I could count on getting me from point A to point B and back without the worry that I was going to be hoofing it for help because of an engine failure. So now you know why I have little faith in the reliability of the 292 I-6 and why I think they are best suited for use in a light (1/2 ton) truck, or better yet, a car. That's why I called it a glorified car engine.

[bigblockv6]

All the Chevrolet engines whether small or bigblock V8 and sixes were nothing but passenger car engines. Chevrolet even converted the big block V8 into a truck engine by adding an extra compression ring to the pistons, adding an inch to the deck height and there the 366 and 427 trucks engines were born, truly over glorified passenger car engines and GMC was forced to drop their V6 for these junk piles in the mid 70's.:pullinghairout:

[TJ's GMC]

TJ, speaking of acceleration was there a noticeable improvement when you added the 4bbl? One of the drawbacks of the 305 is it has a poor power to weight ratio that's why I prefer the larger displacement V6's. The 305 shares the same block as the rest of the family of 60 degree V6 engines up to the 478, so that makes it really heavy for it's smaller displacement. If you would like to know more on the development of these engines go to Jolly's 6066 GMCguy website and check out the Sept 1959 issue of Popular Science. They actually tested a 1bbl 305 in a prototype 1959 Suburban, being that it was in a smaller and lighter truck the performance was more V8 like of that era.:thumbsup:

Big improvement for sure...and that's with the 4 barrel mounted on a 4 to 2 adapter. It should help even more when I have the intake machined to directly fit the carb. The split exhaust made for a nice improvement as well. I'll check out the sight for that issue! Thanks!

[TJ's GMC]

Greetings again TJ, and everyone else in the Club!

As to why I disfavor the 292 I-6, I'll try to be as brief as possible. My Dad bought that '63 Chevy C-30 in 1966 with 42,000 miles on the odometer, and at that time with three new pistons in the engine. After putting on another 3,000 miles, he came home with the engine knocking like crazy. This was in 1968, and I was in high school at the time, taking an auto mechanics course, and I diagnosed the problem (correctly I might add) as being a rod bearing knock. We dropped the oil pan, and it didn't take long to determine that the # 1 rod bearing was totally pounded out. We ordered a new (not rebuilt) short block from our local Chevy dealer, and installed it in an unheated garage in 20 degree below zero weather. Now let me tell you that you only worked on it for about 15 minutes at a time, and then had to go in and get warmed up before continuing to work on it on and off until it was completed. Now, as to problems with the new short block, the engine ran pretty much quietly except for the fact as more miles were racked up, and by the time there was 10,000 miles on that new block, that 292 developed a serious case of piston slap. Remember me mentioning earlier that the original engine had 3 new pistons in it when my dad bought the truck with 42,000 miles on it? It didn't matter whether the engine was cold, or at operating temperature, you could hear every piston in that engine slapping merrily away. Dad turned the truck over to me, and when there was about 70,000 miles on that 292 replacement engine, I knew at some point the dam* thing was going to leave me stranded high and dry somewhere. A neighbor had a 1962 GMC 3/4 ton pickup that he had retired mostly due to the body being pretty rusty. I bought that truck and took the 305 BB V-6 out of it and put it in my '63 Chevy. Putting that BB V-6 in my truck was the best decision I ever made, because it was an engine that I could count on getting me from point A to point B and back without the worry that I was going to be hoofing it for help because of an engine failure. So now you know why I have little faith in the reliability of the 292 I-6 and why I think they are best suited for use in a light (1/2 ton) truck, or better yet, a car. That's why I called it a glorified car engine.

Man, you sure had some bad luck with that engine. Sorry to hear about that. I never had those problems with mine....at 147,000 and being 50 years old I was doing burnouts and reving my worn out 292 up to 5000 RPM. haha Never knocked and no piston slap, but after an extra 2000 miles put on it, it developed valve train problems. Had no power and would sputter on take off....then it would be fine.....valves were recessed in the head causing them to hang open. Also only had 95 psi in all cylinders and 5 psi oil pressure at idle, but it Never left me stranded anywhere....even with all the problems I encountered during my final drive...she still ran and then died in the driveway. I had to have the valves adjusted at .006 clearance just for it to run somewhat smoothly. lol So yeah, I haven't had quite the same issues, but for an old engine that had a 3600 rpm redline from the factory that could do 5000 rpm I'd say that was pretty good. haha But onto the V6 again, I've never had a smoother running 50 year old engine in my life. This thing never misses a beat! After giving this thing a full tune up and valve adjustment this motor gives me confidence while I'm on the road...which is a plus being that its 50 years old with almost 200,000 on it and only 5 psi lost in the cylinders. They're one heck of an engine. Only engine I have that could idle up a hill lugging down to 250 rpm. :thumbsup:

[TJ's GMC]

Thanks for all the knowledge guys! :thumbsup:

[bigblockv6]

Big improvement for sure...and that's with the 4 barrel mounted on a 4 to 2 adapter. It should help even more when I have the intake machined to directly fit the carb. The split exhaust made for a nice improvement as well. I'll check out the sight for that issue! Thanks!

It will definitely make a bigger improvement once you machine the manifold. Many years ago I tried the 4 to 2 adapter and the results were abysmal, the idle would fluctuate and when the secondary's kicked in it would stumble for a couple of seconds.:pullinghairout: I suspect it was a very poor quality adapter that leaked vacuum. All in all there is only so much fuel that you can squeeze in a small opening.

[TJ's GMC]

It will definitely make a bigger improvement once you machine the manifold. Many years ago I tried the 4 to 2 adapter and the results were abysmal, the idle would fluctuate and when the secondary's kicked in it would stumble for a couple of seconds.:pullinghairout: I suspect it was a very poor quality adapter that leaked vacuum. All in all there is only so much fuel that you can squeeze in a small opening.

Mine idles perfectly, but has the same problem when the secondaries kick in....In 4th if I stuff it to the floor the thing jerks and rattles then clears up. lol I suspected either no vacuum advance or to much fuel for a small opening. But if I quickly ease into full throttle it responds fine. So for now I've left it cause its running so good. But when I get my 66 done I'm gonna get into this one. The improvement was major over the 2 barrel. With the 2 barrel I couldn't even rev the thing past 2500 rpm to shift or it seemed to take a month of sundays to get there...hence why I'm sure that old carb was plugged up. Lugging it into 4th proved faster than reving it. It actually would accelerate faster when I had the truck loaded down, least it sure felt that way.lol But once the 4 barrel went on, shifting at 2500 has been the best rpm. And when I split the exhaust, 2700 is now a good rpm.

[bigblockv6]

Talking about who at GM designed the V6, well about 14 years ago a GM engineer that was involved with the development of these engines stumbled into Jolly's site and was quite surprised that there were people that were interested in these engines. His last name was "Cleary" and that's what he went by. He had mentioned early prototypes let loose and scattered easily, more balancing was required. Also the reason for the spark plugs inside the "V" was because during testing one of the engineers went to change the spark plugs and ended up burning his hand on the manifold so spark plugs were relocated inside the "V". Cleary stepped away from that in 1960 or so, he mentioned at that time they were working on Diesel versions. I did save the emails in my old computer, if I get it hooked up I may be able to retrieve it to share with everyone. I also contacted Cleary once myself.

[TJ's GMC]

Talking about who at GM designed the V6, well about 14 years ago a GM engineer that was involved with the development of these engines stumbled into Jolly's site and was quite surprised that there were people that were interested in these engines. His last name was "Cleary" and that's what he went by. He had mentioned early prototypes let loose and scattered easily, more balancing was required. Also the reason for the spark plugs inside the "V" was because during testing one of the engineers went to change the spark plugs and ended up burning his hand on the manifold so spark plugs were relocated inside the "V". Cleary stepped away from that in 1960 or so, he mentioned at that time they were working on Diesel versions. I did save the emails in my old computer, if I get it hooked up I may be able to retrieve it to share with everyone. I also contacted Cleary once myself.

If you could find those that would be cool! By the way I read the article...Lot of neat info right there. On another note I've been driving my gmc around in the snow today. lol Even did a burnout! haha Headlights, windshield wipers, and heater all on and no problems. PO took the original heater cables and control panel out cause they were seized up so I settled for a select switch from Napa and manually set the vents so I get hot air. No fogged up windows now(hopefully). lol Need to drive it some more and see how well the defrost works, but it only took a couple seconds for that cab to get warm.

[George Bongert]

All the Chevrolet engines whether small or bigblock V8 and sixes were nothing but passenger car engines. Chevrolet even converted the big block V8 into a truck engine by adding an extra compression ring to the pistons, adding an inch to the deck height and there the 366 and 427 trucks engines were born, truly over glorified passenger car engines and GMC was forced to drop their V6 for these junk piles in the mid 70's.:pullinghairout:


Greetings bigblockv6!

I can't help but agree with you, and I too am saddened by the fact that GM discontinued the Big Block V-6 engines. Their durability put all other engine designs to absolute shame, no matter who the engine manufacturer was. By the way, I failed to mention that my old '63 Chevy was traded in for a brand new Dodge one ton pickup. Apparently the original owner of my '63 Chevy was not too happy with the fact that he had to replace 3 pistons in the original 292 I-6, and the fact that they probably were not all replaced at the same time resulting in more than one engine tear down. I'm not sure what engine (V-8 or Slant I-6) the Dodge truck that he bought had in it, but I will go as far as to say that even the Dodge Slant I-6 was a better engine than the Chevy 292 I-6.

[Funky61]

I found one email in the archives that Pete (referenced) YAY for the Archives and Jeannie.

http://6066gmcclub.com/forum/showthread.php?p=16253&highlight=Cleary#post16253

[TJ's GMC]

I found one email in the archives that Pete (referenced) YAY for the Archives and Jeannie.

http://6066gmcclub.com/forum/showthread.php?p=16253&highlight=Cleary#post16253

That was neat! Thanks for sharing!

[bigblockv6]

I found one email in the archives that Pete (referenced) YAY for the Archives and Jeannie.

http://6066gmcclub.com/forum/showthread.php?p=16253&highlight=Cleary#post16253

Thanks Funky61, you saved me the hassle from looking it up for now anyway. I do have one email to look up where I directly contacted Cleary with some more questions. For now though this is really good:upyes:

[bigblockv6]

Greetings bigblockv6!

I can't help but agree with you, and I too am saddened by the fact that GM discontinued the Big Block V-6 engines. Their durability put all other engine designs to absolute shame, no matter who the engine manufacturer was. By the way, I failed to mention that my old '63 Chevy was traded in for a brand new Dodge one ton pickup. Apparently the original owner of my '63 Chevy was not too happy with the fact that he had to replace 3 pistons in the original 292 I-6, and the fact that they probably were not all replaced at the same time resulting in more than one engine tear down. I'm not sure what engine (V-8 or Slant I-6) the Dodge truck that he bought had in it, but I will go as far as to say that even the Dodge Slant I-6 was a better engine than the Chevy 292 I-6.

That was a sad day for me back in Nov 1974 when went over to our GMC dealer to pick up a new light switch for the 68 before my father found out I broke it to pieces, I was only 15. Anyway there was not one Medium duty truck or larger 7500 series truck on the lot with a V6.:banghead: I was quite surprised to see a J-7500 series with a 427 V8 for the first time. Some 6 months prior to that just about every medium duty( at least 25-30 trucks) all 7500 series trucks were V6 equipped, my impression then was the V6 was alive and well and they had no problem selling them off. Funny thing was in November there was still quite a few V8 74 medium duty trucks left over with the mix of 75 models.

[TJ's GMC]

That was a sad day for me back in Nov 1974 when went over to our GMC dealer to pick up a new light switch for the 68 before my father found out I broke it to pieces, I was only 15. Anyway there was not one Medium duty truck or larger 7500 series truck on the lot with a V6.:banghead: I was quite surprised to see a J-7500 series with a 427 V8 for the first time. Some 6 months prior to that just about every medium duty( at least 25-30 trucks) all 7500 series trucks were V6 equipped, my impression then was the V6 was alive and well and they had no problem selling them off. Funny thing was in November there was still quite a few V8 74 medium duty trucks left over with the mix of 75 models.

Would have been nice if they kept the V6. But the problem is every darn person has to have that stinkin 350. And because of them, guys like us who want to keep the v6 almost can't because parts are getting more and more scarce by the day. It makes me upset when I see people on forums that have a really NICE gmc with a good running V6....and what's the First thing they say..."I'm gonna swap it for a 350 and th350" Its like Really? REALLY? You couldn't have bought a Chevy and gone cheap on that? I don't know, its just sad to see perfectly good engines go to the scrap yard cause people don't think they are worth anything.

[bigblockv6]

I've always said that the sbc 350 is a major national obsession :pullinghairout: When these guys talk about doing this swap they think it's like something real special, there are so other many alternatives today like the newer GM LS engines. I like the idea of just going to a larger displacement V6 specially 401 and up and there you have a substantial power increase and something that's different than that ubiquitous generic bowtie powerplant:lolsmack2:

[TJ's GMC]

I've always said that the sbc 350 is a major national obsession :pullinghairout: When these guys talk about doing this swap they think it's like something real special, there are so other many alternatives today like the newer GM LS engines. I like the idea of just going to a larger displacement V6 specially 401 and up and there you have a substantial power increase and something that's different than that ubiquitous generic bowtie powerplant:lolsmack2:

I hear ya! Lotta people are so stuck on "Best bang for the buck" "If it ain't cheap it ain't worth it" and all that stuff. Its like really....why do you need to go 0 to 55 in 2 seconds? My 305 pulls me to 55 no problem...not as fast as a 350, but it still does effortlessly. And sounds so dang good to! lol

[BobBray]

The GMC V-6 family of engines was designed in the late 50's to replace the two series of GMC manufactured straight 6's along with the 'borrowed' Pontiac and Oldsmobile V-8's. The V-6 idea was actually very rational as the majority of truck engines at the time were 6 cylinders. A 60 degree 'V' design was selected for compactness, 120 degree firing intervals, and a short strong crankshaft. The engines were very 'oversquare' (large bore, short stroke) to provide flat torque curves and low piston speeds. Most every other feature of these engines was designed for maximum durability, like oversized water and oil pumps, large bearings, and high quality materials. For very large trucks and fire apparatus, the basic design could be stretched into a V-12 (later a V-8 as well). It would seem that the design was intended from the start to be made in a diesel version as well.

No question the GMC V-6 was far more durable than any contemporary passenger car/light truck engine, but I think it is interesting to compare the V-6 to contemporary medium/heavy truck gasoline engines. Again, the GMC proved superior to engines like the International Red Diamond and V-401/478/549, the Ford Super Duty 401/477/534, and the REO (later White) V-8's. The GMC's matched or beat those other engines in output but were more durable, lighter (I know, hard to believe!), more compact, and delivered better fuel economy.

[TJ's GMC]

The GMC V-6 family of engines was designed in the late 50's to replace the two series of GMC manufactured straight 6's along with the 'borrowed' Pontiac and Oldsmobile V-8's. The V-6 idea was actually very rational as the majority of truck engines at the time were 6 cylinders. A 60 degree 'V' design was selected for compactness, 120 degree firing intervals, and a short strong crankshaft. The engines were very 'oversquare' (large bore, short stroke) to provide flat torque curves and low piston speeds. Most every other feature of these engines was designed for maximum durability, like oversized water and oil pumps, large bearings, and high quality materials. For very large trucks and fire apparatus, the basic design could be stretched into a V-12 (later a V-8 as well). It would seem that the design was intended from the start to be made in a diesel version as well.

No question the GMC V-6 was far more durable than any contemporary passenger car/light truck engine, but I think it is interesting to compare the V-6 to contemporary medium/heavy truck gasoline engines. Again, the GMC proved superior to engines like the International Red Diamond and V-401/478/549, the Ford Super Duty 401/477/534, and the REO (later White) V-8's. The GMC's matched or beat those other engines in output but were more durable, lighter (I know, hard to believe!), more compact, and delivered better fuel economy.

WOW! Thanks the sharing! Has anyone dynoed these that you know of? I'd be interested in seeing the torque curve. A friend of mine said the main bearings on these were as big as a 7.3 diesel engine's main bearings. I know GM made the toro flow but from what I've been reading it wasn't a very good success? There is one for sale about 45 minutes from me for $500. Supposedly runs to. Wow...a GM V6 being lighter than something is surprising. lol Thanks.

[bigblockv6]

The main bearing journal got even bigger on 73-74 478M V6 engines, bigger main caps, larger bolts ad just a lot more reinforcing in the main saddle area.

[TJ's GMC]

The main bearing journal got even bigger on 73-74 478M V6 engines, bigger main caps, larger bolts ad just a lot more reinforcing in the main saddle area.

Any particular reason why that you know of? Like they weren't big enough already. lol!

[bigblockv6]

Nothing that I heard of but in 73 the whole line of V6 engines other than the 305(the 305 originally was slated to be discontinued for 72 but they decided to keep it going) went through upgrades. The gas engines only used 2 bolt main yet the Diesel versions had 4 bolt mains, actually cross bolt mains. Possibly there may have been some bottom end failures with 478's in the 7500-8500 series trucks, I have a 73 478M and the main caps are so much larger and contour better with the bottom of the block. I'll takes some pics of both the new style caps and old caps for a comparison and post them sometime this week.

[Dave Boboltz]

I worked at GMC Truck and Coach in Pontiac beginning in 1974 as a co-op student, but by that point in time, the area of Plant 2 along South Boulevard where the V6 and V12 were made was not being used much, maybe only for service parts. The part of the plant where the engine line was located was called building 29. All of the tooling was shipped out around 1977 to make room for the GMC Motor Home in building 29. The Motor Home had been built in Plants 3-4-5 on the other side of Woodward, and was relocated so the G-van could be built there. I don't know where the engine tooling went.

I reviewed the James Cleary email from 2004 and I only recognized one name from the list of people that helped design the engine. I have a friend who told me that his father is listed on one of the patents for the engine (last name is Sherrick).

Dave Boboltz, Waterford MI, 1964 K1002 305E

[bigblockv6]

Dave, after the tooling was shipped out were service parts manufactured at a different plant or do you think that was just the final end of the GMC V6. Evidently GMC must of stockpiled a good amount of parts, back in 1984 I looked into buying a new 432 V6 and it was available through the dealer.

[Dave Boboltz]

Big Block V6, that is a great question and I don't know the answer to that. I did send Cleary an email so maybe I can learn more. Or there is another guy who lives nearby who has some amount of historical information (Don Meyer).

I suspect that the tooling went somewhere that would be capable of making service parts. It would be interesting to know where that tooling is now.

Dave Boboltz, Waterford, MI

[bigblockv6]

It would be interesting to know what became of the tooling. From what it looks like in the email, Cleary was no longer in the V6 development sometime in 1960. He was not aware of the 379,432 and 637 engines.

[TJ's GMC]

So here's a question....anybody know why a small single barrel and then two barrel carb were used on these engines? I'm assuming for low end power and fuel mileage? Might be a dumb question, but with the large bore I would have thought a bigger carb would have been used.

[bigblockv6]

The one barrel did not work out well with the 305 engine by 1961 the 305D 2bbl engine came in to replace the 305A even though it was still available. 125 net horsepower to carry around that much weight was really underpowered for the 305. The 2bbl brought it up to 142 net horsepower then with more improvements for 1966 to 157 horsepower. Possibly mileage may have been why a 1bbl was used. Originally the prototype trucks used were lighter 1958-59 trucks and the 1bbl version was more than adequate.

[TJ's GMC]

The one barrel did not work out well with the 305 engine by 1961 the 305D 2bbl engine came in to replace the 305A even though it was still available. 125 net horsepower to carry around that much weight was really underpowered for the 305. The 2bbl brought it up to 142 net horsepower then with more improvements for 1966 to 157 horsepower. Possibly mileage may have been why a 1bbl was used. Originally the prototype trucks used were lighter 1958-59 trucks and the 1bbl version was more than adequate.

Ah, Ok. I watched a video of a 305A running...man you could hear that thing Breath. lol I was like yeah....that carb is a bit small. You know what improvements were made in 66? I remember running the numbers on mine with a fellow forum member, and my 305 in my 64 looked to be a 67 series engine. Did the 305E ever come in medium duty trucks? Cause mine had the governed dizzy on it.

[bigblockv6]

A new cam along with different count timing chain and sprockets were some of the changes, at some point up to 66 larger valves were used on the 305 engines as well. Medium duty trucks used 305 engines from their beginning in 1960 all the way up to the very last in 1974:thumbsup:

[bigblockv6]

:lolsmack2: I should have included this in my previous response. Yes 305E engines they were used in 3500, 4000 and 4500 series medium duty trucks.

[bigblockv6]

Light duty trucks too were available with governors.

[TJ's GMC]

A new cam along with different count timing chain and sprockets were some of the changes, at some point up to 66 larger valves were used on the 305 engines as well. Medium duty trucks used 305 engines from their beginning in 1960 all the way up to the very last in 1974:thumbsup:

:lolsmack2: I should have included this in my previous response. Yes 305E engines they were used in 3500, 4000 and 4500 series medium duty trucks.

Light duty trucks too were available with governors.

Ah ok, yeah....I had to get a new dizzy cause the old was was frozen up....the governed vacuum pump was seized or something. Here's another question....any particular reason why the compression was made so low?

[bigblockv6]

I'm not absolutely sure but from what I recall The idea of having low compression was for achieving low end torque.

[Ed Snyder]

Or there is another guy who lives nearby who has some amount of historical information (Don Meyer).

Dave Boboltz, Waterford, MI

I'm glad to hear that Don Meyer is still alive, Dave. I corresponded with him a few times several years ago. I sent him color copies of all my 60-66 GMC sales brochures that he didn't have. He seemed really appreciative. I don't remember exactly where I first got his contact info, but do remember him being identified as the official GMC historian. I'm guessing he might be in his 80s by now.

[BobBray]

I talked with Don Meyer a few times over the years, he is is very knowledgeable about GMC in the old days.

As for the low compression, there are a couple of factors. First, large bore engines can be more prone to knocking, all other things being equal. Also, gasoline truck engines of the era were designed to use low octane (cheap!) fuel. None of the GMC V-6's contemporaries had very high compression, most were in the 7:1 to 8:1 range. These engines were designed to be abused!

[TJ's GMC]

I talked with Don Meyer a few times over the years, he is is very knowledgeable about GMC in the old days.

As for the low compression, there are a couple of factors. First, large bore engines can be more prone to knocking, all other things being equal. Also, gasoline truck engines of the era were designed to use low octane (cheap!) fuel. None of the GMC V-6's contemporaries had very high compression, most were in the 7:1 to 8:1 range. These engines were designed to be abused!

You got that right. lol I've ran 87 in this thing no problem at all. Though I prefer 91, it's nice to know the engine will run happily on low octane. :thumbsup:

[TJ's GMC]

I'm glad to hear that Don Meyer is still alive, Dave. I corresponded with him a few times several years ago. I sent him color copies of all my 60-66 GMC sales brochures that he didn't have. He seemed really appreciative. I don't remember exactly where I first got his contact info, but do remember him being identified as the official GMC historian. I'm guessing he might be in his 80s by now.

Wish I could meet this guy!

[TJ's GMC]

I'm not absolutely sure but from what I recall The idea of having low compression was for achieving low end torque.

That makes sense, but man....imagine what a compression boost would do. lol

[bigblockv6]

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

[BobBray]

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

[TJ's GMC]

GMC did have what the called the HC(High Compression) series of V6 engines, never installed in trucks. They were sold for industrial purposes, though they called them high compression the ratio did not exceed 9 to 1.

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

I'll bet the extra compression boost helped alot though. Would be neat to find one.

[Clyde]

Don Meyer, GMC Historian can be reached at 248-693-1227, he is in Michigan. My 1966 Owners manual specifies 92 octane gasoline, back when these trucks were new this was considered regular gas, today this is considered high octane. Anyone over 65 will remember being able to purchase 110 to 120 octane gas without any problem at most all gasoline retailers.

[Cayoterun]

Yes they did. I think the idea was that those engines were primarily for use with propane/LNG/CNG fuels.

I wonder if any of the high compression engines ended up in forklifts.

Great thread. Enjoy reading it.

All the the V12s, I've ever been around came factory equipt with hi-compression pistons since all of them was used as irrigation power plants, and used natural gas or propane.
I was never around V6s, except a few 478s on pumps, too.

[TJ's GMC]

Don Meyer, GMC Historian can be reached at 248-693-1227, he is in Michigan. My 1966 Owners manual specifies 92 octane gasoline, back when these trucks were new this was considered regular gas, today this is considered high octane. Anyone over 65 will remember being able to purchase 110 to 120 octane gas without any problem at most all gasoline retailers.

Cool! Thanks for his number! Yeah, the good ol days when fuel was really fuel. lol

[Clyde]

The Pontiac Oakland International Chapter #93 (POCI) was established in 2007. The GMC Times is published 6 times a year by the GMC Truck Chapter of the POCI. The dues are $20 per year, I feel it is well worth joining as they are dedicated to our beloved GMC's. Anyone interested in joining can contact: Paul Bergstrom, 1165 County Road 83, Maple Plain, MN 55359 (763) 479-2248 pontiacpaul@gmail.com. You can also check them out at gtcpoci.info.

[TJ's GMC]

The Pontiac Oakland International Chapter #93 (POCI) was established in 2007. The GMC Times is published 6 times a year by the GMC Truck Chapter of the POCI. The dues are $20 per year, I feel it is well worth joining as they are dedicated to our beloved GMC's. Anyone interested in joining can contact: Paul Bergstrom, 1165 County Road 83, Maple Plain, MN 55359 (763) 479-2248 pontiacpaul@gmail.com. You can also check them out at gtcpoci.info.

Thanks for the info Clyde. :thumbsup:

[TJ's GMC]

Well I did a test for the heck of it today....sorry...no pictures or video. Anyhow, I towed my 1947 Case VAI and that was loaded on a double axle trailer....so the load wasn't light....Bout 6000+ pounds. Well...I really hate the SM420 for towing applications because when you go from 3rd to 4th shifting at 3000 RPM things drop to 1500 rpm and pulling a slight grade things pretty much Stay there. lol I was at half throttle and slooooooooooooooooooooooooooooooooowly picking up speed. Good thing the highway leveled out. haha But on flat ground getting up to 55 no problem at all. GOOD torque in the low range....motor had NO problem at ALL pulling from 8 MPH in 3rd gear...bout 900 rpm lug if I remember right. Starting on Flat ground...rev it quick in granny then shift to 2nd and shift at 2700 rpm into 3rd then at 2700 rpm into 4th and sitting at around 2500 going down the highway...which was around 50-55. On a slight incline I would shift from 2nd to 3rd at 2700 then 3rd to 4th at 3000 and keep it half throttle the rest of the way. There was a hill I pulled in 4th no problem....bout 40 mph and hill ended before I needed to downshift. Motor has some guts for its smallish size as far as cubes go. But a gear vendors OD I think is needed now. Mainly to have something between 3rd and 4th for towing cause the engine hates that drop. I'll say one thing...I'm sure the 4 barrel and split exhaust helped a ton. lol If I ever run across a 478 I think I won't be able to resist a swap. LOL! Love my 305 v6 though! Good running engine...did what it needed to do with no problem and pulled hard with no complaints. She's a runner. :)

[TJ's GMC]

I do have a question though....anyone have an NP435 tranny behind their v6? Looking at the closer split between gears I may lean towards a swap. Looked into a gear vendors OD and said "**** No!!!" when I saw the price. lol

[bigblockv6]

In later years like 1967-69 there was a NP435GA that was a close ratio version, didn't have the granny 6.68 to 1 ist gear.:thumbsup:

[Ed Snyder]

I do have a question though....anyone have an NP435 tranny behind their v6? Looking at the closer split between gears I may lean towards a swap. Looked into a gear vendors OD and said "**** No!!!" when I saw the price. lol

My 2WD '67 has the NP435. Per the '67 sales brochure, it was the "heavy duty" optional 4 speed compared to the SM420. Starting from a stop in normal driving, you still start in synchro second, just like in the SM420. Non-synchro first is definitely a taller gear in the NP435, though, compared to the SM420. The shift pattern is different too -- reverse is to the right and down. The "bar" in the H between second and third is pretty narrow too. If you're used to shifting from second to third in an SM420, you'll overshoot third every time in the NP435 and go too far to the right and end up above reverse.

[BobBray]

My '67 has the NP435GA. The ratios are 4.56:1 1st., 2.28:1 2nd., 1.31:1 3rd., 1:1 4th.. Quite a bit closer than an SM420 as Peter and Ed pointed out! Be advised that Dodge and Ford also used a lot of NP435's, and most are wide ratio like the SM420's. Also, the NP435 was common in GMC medium duty trucks, but again these were wide ratio versions. The NP435GA was very well suited for the 351E, that engine's low r.p.m. torque didn't need the lower 1st./2nd./3rd. ratios.

[TJ's GMC]

Thanks guys! Yeah, according to the specs I've seen my SM420 has a 7.06 1st gear. I never did get what it was with GM and these crazily wide ratio trannys. They are horrible for towing heavy stuff. I mean 1st, 2nd, and 3rd aren't to bad....but 3rd is so low that you can't rev it high enough to shift to 4th. lol Unless on perfectly flat ground or downhill. Or you shift at 5000 rpm. haha For the occasional heavy towing I'm doing I think it'll work OK. Hoping to search so local yards though.

[68crackerbox]

Greetings TJ!

As to who at GM came up with the design of the big block V-6, well, that's information that I don't have, although I also would like to know who that person was. As to the comparison between the 292 I-6 and the various versions of the GMC Big Block V-6's, I'll take the Big Block V-6's any day of the week before I would take the 292 I-6. As many here know, I once owned a 1963 Chevy 30 Series (1 ton) pickup originally equipped with the 292 I-6 which I eventually replaced with a GMC 305 V-6. Now, there will be those here who will disagree with me, but my feeling is that the 292 I-6 was nothing more than a glorified car engine put in a truck, and not necessarily designed to be a truck engine, although GM engineers would differ with me on that point. I know, because my Dad and I had plenty of problems with the 292. When I replaced the 292 with the GMC 305 V-6, those problems all disappeared. Now, having said that, yes, the 292 would be faster on acceleration and rev higher than a BB V-6, but as you indicated, the GMC V-6 will outlug the 292 six ways from Sunday, and all in all is a much more durable engine than the 292 ever was or will ever be. I know you have several 292's in your collection, and that you are very pleased with them. My experience has been the 292 is an engine (along with a few other GM engines) that I do not strongly favor.

On a lighter note, Merry Christmas to all here in the 6066 GMC Truck Club!
we had 292's in c/50 ten wheelers back in the 70's and they pulled and ran better than 350's and we were young then, alway kept to the floor(4000 rpm) and never had one come apart. they did a good job.

[68crackerbox]

also had a 65 4000 ten wheeler with a 351 v6 in it paid 500. for it. and it would out pull a 350 too. and couldn't blow it up. it just kept on running no matter how hard you pushed it.

[TJ's GMC]

we had 292's in c/50 ten wheelers back in the 70's and they pulled and ran better than 350's and we were young then, alway kept to the floor(4000 rpm) and never had one come apart. they did a good job.

Same experience for me. lol Reved my stock 292 to 5000 RPM a few times doing burnouts. Thing ran like a champ...even when the valve train went south while I was driving it...still made it home. My V6 has been the same way, I am much more conservative with it....Highest I have reved it is 3400 RPM and I Don't do it often. 2700 is what I shift at.

[tommr]

http://youtube.com/watch?v=75UFbtNlmYgPrevious owner of our bus told me over the Christmas Holiday he cranked it up to 80mph driving east from CA back in the early 70s. 55 mph is 2900rpm(direct drive Spicer 4 spd) on the 401M. I don't even want to know what rpm 80mph was. He had to shut it down and let it cool after he sucked the radiator hoses shut. 55 mph with the new Allison 1000 is 2200rpm in overdrive. Theres north of 450k on this engine and it still has 145-150psi in all cylinders. First rotation goes right to 95psi. Spark plugs and exhaust pipe are medium ashy gray. No smoke and uses about 1/2 qt per 1000 miles. No equal to this engine. One tough *****. Youtube link not working for some reason. just type 1947 Allison into the Youtube search window.

[TJ's GMC]

http://youtube.com/watch?v=75UFbtNlmYgPrevious owner of our bus told me over the Christmas Holiday he cranked it up to 80mph driving east from CA back in the early 70s. 55 mph is 2900rpm(direct drive Spicer 4 spd) on the 401M. I don't even want to know what rpm 80mph was. He had to shut it down and let it cool after he sucked the radiator hoses shut. 55 mph with the new Allison 1000 is 2200rpm in overdrive. Theres north of 450k on this engine and it still has 145-150psi in all cylinders. First rotation goes right to 95psi. Spark plugs and exhaust pipe are medium ashy gray. No smoke and uses about 1/2 qt per 1000 miles. No equal to this engine. One tough *****. Youtube link not working for some reason. just type 1947 Allison into the Youtube search window.

That's a cool bus! Yes, The ol V6 was GM's best motor they ever made. Interesting design, but a really neat engine proven reliable and durable.

[George Bongert]

Greetings to all!

I've been following this topic with great interest, and all I have to add to it is that it's a crying shame that GM ever discontinued production of these extremely reliable and durable engines! Just imagine what could have been if these engines were still produced with the technology that we have available today. Just plain a doggone shame that these engines have gone the way of the Dinosaurs! For those of you out there that have any of these engines lying around that can be restored--for God's sake--please don't scrap them!! And shame on anyone that pulls a Big Block V-6 out of a 60-66 GMC Truck in favor of replacing it with a Chevy 350 V-8!! To me, that's a Sin of the worst kind!

[bigblockv6]

The GMC V6 family of engines was prematurely phased out,:pullinghairout: I would have to say it was all a matter of dollars and cents with GM. You could see the trend from the late 60's of incorporating Chevrolet engines and more interchangeability lead to the final demise of the GMC V6 after 1974:ahhhh:

[TJ's GMC]

Greetings to all!
And shame on anyone that pulls a Big Block V-6 out of a 60-66 GMC Truck in favor of replacing it with a Chevy 350 V-8!! To me, that's a Sin of the worst kind!

AMEN to THAT!

[TJ's GMC]

Anyone know the intake and exhaust valve size on the 305 v6?

[POWERSTROKE]

http://youtube.com/watch?v=75UFbtNlmYgPrevious owner of our bus told me over the Christmas Holiday he cranked it up to 80mph driving east from CA back in the early 70s. 55 mph is 2900rpm(direct drive Spicer 4 spd) on the 401M. I don't even want to know what rpm 80mph was. He had to shut it down and let it cool after he sucked the radiator hoses shut. 55 mph with the new Allison 1000 is 2200rpm in overdrive. Theres north of 450k on this engine and it still has 145-150psi in all cylinders. First rotation goes right to 95psi. Spark plugs and exhaust pipe are medium ashy gray. No smoke and uses about 1/2 qt per 1000 miles. No equal to this engine. One tough *****. Youtube link not working for some reason. just type 1947 Allison into the Youtube search window.

TOMMR - 80 mph as geared was at 4218 rpm. Just a little outside the recommended operating range!

[TJ's GMC]

TOMMR - 80 mph as geared was at 4218 rpm. Just a little outside the recommended operating range!

And I'm scared to get mine past 3500! LOL!

[POWERSTROKE]

And I'm scared to get mine past 3500! LOL!

If the valves don't float, keep your foot in it!

[TJ's GMC]

If the valves don't float, keep your foot in it!

I'm good. lol My V6 is running like a top and I wanna keep it that way for a long time. haha Have no doubt in the motor, but never hurts to be easy on them....occasional burnout or two works for me. lol!

[401bluebird]

I found this thread from some time back this morning. I followed with interest when discussing driving in heavy haulers with the V6s, as I have a 1960 GMC 35' motor home conversion All-American bluebird Coach with a Clark 5-speed trans behind the original 401 V6 engine.

I drove it quite a bit after I purchased it in 1987, going to British Columbia, Canada. I got 6 mpg consistently, which I thought it was all it would get, but the previous owner told me he got 10 mpg on long trips. After several trips I did something I should have done after purchase--I pulled the plugs and saw that they were close to being gas fouled. The 2-bbl carb was spilling fuel into the air stream while running. After corrected, I was getting close to 10 mpg @ 60-65 mph.

My rig weighs 23000 pounds, which is a lot of mass to climb hills. The trans has a bad gap in the 3-4 shift, which becomes quite annoying when climbing long grades, which are numerous here in the West. I learned to simply be patient and stay in the lower gear at a slower speed.

I have plans to return this to the road after replacing the wheels and tires to eliminate the old rag 20" tires on split rims. I also have a new, old stock (2001) Holley pro-jection throttle body retrofit EFI system which I intend to install. It is 2-bbl sized which should ease the adaptation to the pre-magnum 2-bbl intake manifold.

Though slow on grades, the coach performs very well on the flats, and steers and rides quite comfortably. I recently had the opportunity to acquire a low-mileage 478-M with the idea I could swap it into the Bluebird, but I think I am going to stay with the workhorse 401.
Regards, Andy Carlson, Ojai CA

[BillT]

The GMC V6 family of engines was prematurely phased out,:pullinghairout: I would have to say it was all a matter of dollars and cents with GM. You could see the trend from the late 60's of incorporating Chevrolet engines and more interchangeability lead to the final demise of the GMC V6 after 1974:ahhhh:

Back around '74, I was talking to the parts manager at a GMC Dealership and he told me that the V-6 did better and was more liked on the East Coast with all the hills we have, but not that favorable on the flat areas in the Central and Western US. He said because of that, the demand was dropping off and they decided to phased it out, to my dis-appointment.

I had both a 6-292 and V-6's. I like them both, but really liked the V-6 in Heavier trucks. My '62 6500 with the 478 was a powerhouse. It would pull a full load of 20,000 lbs like nothing. Hills would not phase it either, lol.

[401bluebird]

The economics of replacing a well regarded engine design with something cheaper has not been only with the GMC V6 family.

In the 1950s Chrysler produced many trucks under the Dodge brand which were fitted with the Chrysler double rockershaft engine, a highly regarded design which became popular for drag racing where they were known as "Hemis". These strong, well built engines were long-lived and very durable. But the complexity of the valve layout and the machined combustion chamber made this an expensive engine to produce--more than the other competitors in the luxury car market.

The replacement was a big block engine which shared a lot of design elements of the small block Chevy V8 and was used from 1958 until 1978. Though nice engines, they weren't anywhere nearly well regarded as what was replaced.

I look at the GMC V6 and I am impressed with the 100% great design incorporated into the engines. I guess 14 years was a good run, though. And here we are, all singing the praise!

-Andy Carlson
Ojai CA

[bigblockv6]

What I would like to add to BillT's response is yes the GMC V6's were great for pulling uphills and I've mentioned this before on Jolly's site which is my Uncle drove prototype GMC Tow Trucks that wr given to the California State Automobile Association(AAA) in the mid 50's which were the 55-59 design trucks with the V6 engines. San Francisco was an excellent test bed as it has a lot of hills as well as real steep hills. As far the west coast and central parts of the country being flat I would say that's is really doubtful that let to the demise of the V6, it was all about dollars and cents from the corporate big wigs, It was just cheaper to use a Chevrolet engine:pullinghairout:, the GMC V6 was known for it's longevity so it was less prone to break down. GMC historian Don Meyer has even said that. Myself growing up in San Francisco in the late 60's and early 70's and being in a family that owned a grocery market I can say the GMC Trucks powered medium and heavy duty trucks by the V6 were very dominant compared to other trucks:thumbsup:

[bigblockv6]

I look at the GMC V6 and I am impressed with the 100% great design incorporated into the engines. I guess 14 years was a good run, though. And here we are, all singing the praise!

-Andy Carlson
Ojai CA[/QUOTE]

14 years not long enough, the V6's could have lasted longer if GM wasn' so cheap, anytime GM has something that's real good they tend to get rid of it. What was apparent though after the demise of the V6 was more Diesel engines were added to the larger Heavy duty series trucks, evidently the 366 & 427 engines couldn't quite muster the duties of the 432 and 478 V6 engines.

[Ed Snyder]

I look at the GMC V6 and I am impressed with the 100% great design incorporated into the engines. I guess 14 years was a good run, though. And here we are, all singing the praise!

-Andy Carlson
Ojai CA

14 years not long enough, the V6's could have lasted longer if GM wasn't so cheap, anytime GM has something that's real good they tend to get rid of it. [/QUOTE]

The GMC dealer where my Dad bought the one ton Suburban new in 1965 once told him that one reason General Motors dropped the V6 was because so many of the GMC dealers were complaining that their repair shops weren't making enough money because the V6s were too reliable and long-lived. Switching to Chevy engines solved that complaint!

[TJ's GMC]

This reminds me of a great 305 V6 vs 350 v8 story a buddy of mine told me. He used to own a 65 GMC LWB C10 with a 305E/sm420 and 3.54 rear gear. He Loved that v6 and wouldn't have traded it for any v8.

Now here's the story:

He and a friend of his were ripping this deck down with their trucks.....his buddy had an early 70's or 80's Chevy 4x4 with a 350/th350. Well he backed up to the deck, and from what I remember hearing....in 1st gear that truck either couldn't spin the tires for it's life.....or they spun and the truck did nothing to that deck. Needless to say.....my buddy pulled up to the deck....hooked up...and in granny low, that v6 tore that deck apart without a thought. :thumbsup:

And don't get me going on 305 v6 vs 305 v8 stories! :teehee: Never will Any chevy engine beat the durability and performance of the v6. Best engine GM ever made, not many can claim an easy 300,000 miles!