Looking for information - Buying a truck

[vwgreg]

This is my first post, great site.

Looking for some information.

In the next couple of days, I’m going to be looking at two trucks, both have flatbeds, duallys, and 4 speeds. One is a 66 which the owner can not take pictures of because he is 90 and the other is a 68 which I have seen pictures of but it needs an up close and personal inspection.

Both of them are in the $2500 range and both of them are 1 ton which will haul what I need to haul - water and waste totes.

The 66 hasn’t run in 24 years, it was parked in a lean too 10 years after the owner bought it to use on his farm, he doesn’t remember why he parked it but it wasn’t mechanical. He mentioned he bought a larger grain truck to use. So I expect the typical mouse house situation and as we discussed it is a Michigan truck with some rust so I am expecting it to be Swiss cheese. He knows it is a v6, his grandson wanted the truck and take the “old crap” out of the truck and put in an LS something. He told him no and decided to sell the truck instead to someone who could use it. He thinks the engine is a 400 cu in engine, so when I get there I will see what it is.

The 68 is about the same but the owner says it has a 351 cu in v6 in it, it looks complete from the images he sent me, a little messed with on the body, it's the same thing - Michigan truck and rust but nothing really bad. He said it has not been started in a long time and never tried so I expect it to be the same as the 66 in the condition of the engine. The owner says there are extra parts to it, the interior looks intact but the images can be deceiving.

Both most likely need brakes and tires. I am going to take the one in the best condition unless I find one for almost nothing (Yes I can dream) that doesn’t need work.

I have owned 67-72 Chevys before, so I am familiar with them but never a the V6 so I am new to them. The better informed I am, the better I can judge the trucks. My Hollenders and my shop manuals are all in storage, so I have to ask others about the trucks because I just do not remember.

1 -any thoughts about these two years of truck? I know the 67-72s have a big following, parts are all over the place it seems but the 66 I am unsure of.

2 - what else should I look for that is unique for a v6 truck?

3 - what transmissions and/or bellhousing works with the V6 engine?

4 - is the clutch hydraulic on these heavier trucks?

Thanks in advance.

[Ed Snyder]

Originally Posted by vwgreg

This is my first post, great site.

Looking for some information.

In the next couple of days, I’m going to be looking at two trucks, both have flatbeds, duallys, and 4 speeds. One is a 66 which the owner can not take pictures of because he is 90 and the other is a 68 which I have seen pictures of but it needs an up close and personal inspection.

Both of them are in the $2500 range and both of them are 1 ton which will haul what I need to haul - water and waste totes.

1 -any thoughts about these two years of truck? I know the 67-72s have a big following, parts are all over the place it seems but the 66 I am unsure of.

2 - what else should I look for that is unique for a v6 truck?

3 - what transmissions and/or bellhousing works with the V6 engine?

4 - is the clutch hydraulic on these heavier trucks?

Thanks in advance.

Welcome to the site, VWGreg! You should be able to get answers to all your questions here. Subject to corrections by others, I'll take a crack at answering your questions.

1. Without seeing either truck, and assuming they are both indeed in the same condition, my own preference would be the '68 truck. Much more rare with a V6, and a more popular body style.

2. Confirm the engine size by looking at the flat spot on top of the block right in front of the passenger side cylinder head.

3. The only bellhousing that works is the one it came from the factory with. Most GM manual transmissions from that era will bolt up to it. However, an automatic trans will require a different and rare flywheel and adapter.

4. Clutches should have mechanical linkages, not hydraulic.

Good luck, and share lots of photos with us!

[Funky61]

Welcome to the forum VWGREG!

You got some great advice from Ed.

Check the Jolly site (Tagged at the top of the forum Page) for more V6 information and lots of details.

https://6066gmcguy.com/

[Prowbar]

As Ed said, look at the engine number to check the actual displacement. The 401 ci (if true) should have been swapped in from a larger truck. The 351 was an option in the pickups in 66 and 67 (68 too?) and is much more desirable over the base 305 ci V6.

When pulling spark plugs, be sure to blow out the spark plug cavities in the cylinder head using compressed air.

The 66 should have a unique hood with the V6 emblems and the GMC turn signal lenses.

[vwgreg]

Just a quick reply. Thanks for all the replies, I really appreciate the advice.

This morning, I saw what was advertised as a 1968 GMC, which turned out to be a 1972 Chevy.

It is rougher than I thought it would be, it needs body work and some parts (door cards and one door handle).

However, it does have a 305 V6 (thanks Prowbar), not a 351 V6 as claimed. I know that's not the original engine, that was a 350 v8 with a hydromatic behind it according to the options list.

I did not find a GVW tag anywhere on the truck, the Vin confirmed it is a Chevy C30 and the options indicate that it is at least a 6600lb GVW, which will work for me.

I don't think the owner knows what it really is or how to figure it out, so I will tell him when I talk to him Monday about what I know to be fair.

As for the condition of the engine, I think it is frozen, I tried with a breaker bar and socket to move it but it didn't move, messed up my back trying. the sparkplugs are out of the head but it is complete. I was very surprised at how big it looked by the way. I know near here there is another 305 engine out of the truck which the owner claims it runs but I don't know if I should bother with it or not, I will make an offer for it if the 66 doesn't look better.


I would post pictures of the truck but not until I talk to the owner to be fair.

[Prowbar]

Hmm. I'd pass on that one if the other is in better shape. There is a large chance that water got into the cylinders because the spark plugs are missing, causing rust and locking up the engine.

Since it is a manual conversion, it can be done properly or shoddy. Have to check for that also.

[vwgreg]

Originally Posted by Prowbar

Hmm. I'd pass on that one if the other is in better shape. There is a large chance that water got into the cylinders because the spark plugs are missing, causing rust and locking up the engine.

Since it is a manual conversion, it can be done properly or shoddy. Have to check for that also.

Well, I do like the 68/72/whatever it is, more. Nothing against 66 or earlier (I like 61/62) but parts are all over the place which makes it easier for me.

I would expect to pull the head and see it full of water. On the other hand, I have located four V6s, three 305, and one 351 under $500 within 100 miles that all claim run. The 351 has one thing I want, a factory-mounted air compressor. The offer I have in mind still sits within my budget with another engine, just getting it swapped out would be a little problem (the engine lift is in the back of my storage container).

I looked at the clutch linkage, it looked alright to me. I tried it and found it to have good resistance, so I have to assume it is functional. If I get this truck and pull the engine, I will surely make sure everything is right.

I just had a thought, I wonder if they just removed the cab and bed and put it all on another chassis. I have to look for the frame serial number - anything is possible.

I did look at the '66, here is what I found.

it looked good from a distance, but up close, you can see the painted rust on the doors and fenders.

The interior is non-existent (meaning no seat covers), raccoons were in it, they ripped everything up, even chewed up the steering wheel (seen this happen a few times with raccoon damage), and raccoon poop everywhere, some fresh. I don't know where they got into the cab but I think the door was left open and shut before I came to see the truck.

The cab has rust, rockers, cab corners, and a windshield area. The floor isn't bad one or two spots of rust our but small. it isn't as bad as I've seen on 73-79 trucks so it is workable for me. What is with these trucks and no wiper arms? these two (1966 and 1968) both don't have them.

It does not run, brought a battery to try (suggestion by the seller) to get it going, but nothing with a little starting fluid. Didn't try much but it is free! it is missing a couple of parts (the fuel pump line to the carb is missing and the regulator). Under the engine, it looks like there is a rear seal leak, the oil has the same smell as what is on the dipstick, which smells odd, something like Castor oil of all things. It is a 305 V6, he said he didn't remember but thought it was a 400 or something like that.

Looking at it for the first time, it has not moved in years, the tires are all flat and dry-rotted. Not too worried about the tires.

It is a 3000, 10k gvw on the tag, which also says it is a 305 V6. It has a 12-foot bed on it but the wood is rotted in the rear which gave me an idea of what was going on below it.

Now the really bad part - there is frame rot in the back at the left rear spring perch, it is a very odd type of rust out both the web and the flange are rusted, I have never seen it like this. I put my finger through it in four or five spots in the area. It looks like the truck was used to move or spread salt or some other very caustic material. It is crusty on the right frame rail, exactly opposite of the rust. I wonder if I can even patch the frame or if this will be a parts truck. I didn't take measurements of the webbing to see if I can get a frame section that size but if I get it, I will find a piece for a repair.

I also found serious rust up near the cab, the rear cab mounts are flakey, and I don't trust them much to hold up without removing the cab to replace them.

So I talked with the owner for about 45 minutes about the truck, about different things, and found out he worked for my cousin in the 1960s, which was nice to know.

However, there were some inconsistencies about the truck that came out, like the title status (*not important to me) so after a while, he was starting to be reluctant to sell it.

Toward the end of the conversation, I made a fair offer, it wasn't close to asking but it was fair for the condition of the truck. He said 'Maybe' but then he said it has been part of the family, blah blah blah, and decided not to sell it at all which I get, I have dealt with elderly people like this most of my life and just don't get upset about it. I told him the offer was good for a couple of days, and if he changed his mind, he could call me.

When I was ready to leave, his son pulled up. I had a nice conversation with him. He filled me in on the truck and what it was used for before it was parked (spreading salt and another caustic material), he said he would talk to his dad about the offer (which he would have said yes to because it wasn't worth much more than that) and see if he would accept it. He said there is a title to it, and he also offered to move it to my place for free (60 miles) if I do buy it but I told him he already said no and the offer is good for a few days.

I was told about another truck, it is a 66 4500(??) grain truck with a v6, it is larger than I want but I will look at it sometime later this week.

[Prowbar]

Hm. That truck is even worse... The 68/72 is better in that case, especially if you can get the running 351 with that price!

The 66 GMC 3000 is a very rare truck actually, not many were sold of that size as a matter of fact.

[vwgreg]

Another update and a question -
I looked at two more trucks this past week, and I don't understand why they are all missing wiper arms but they did.

The 1968/72 was sold from under me, I am a little disappointed but that's how it goes, there is another that popped up and I will see that tomorrow.

I saw the '66 grain truck, it was just too big. I measured the bed - 18 feet long. Before I left, the guy had sold it to another who was there looking at it at the same time.

It was in really good shape but the real problem was it needed brakes all the way around (it stopped but not well) and had a 'knock' coming from the engine, it wasn't a knock like a rod knock but a knock with a ring.

The other I looked at was a 1969 GMC 3000 stake bed with a 305 V6 4sp, GVW 10k.

The owner said that the engine was not original, and the SPID confirmed that fact. He said the owner before him pulled the engine out of a smashed '67, The problem with it is all electrical - no lights, no charging, no blower motor (I am good at sorting out electrical issues). He said the original engine had internal problems and the reason for the swap.

I bought a battery with me, put it in, and got it running. It idled well and moved well, but it seemed to wander all over the place. I spent an hour with the truck, and 15 minutes with the seller, made an offer, and waited for him to tell me either way. I don't think he will accept the offer, he said he had others.

A couple of questions -

I am looking at one-ton trucks which are not easy to find. I ran across a lot of 3/4 ton trucks. I read somewhere that a 3/4 with HD suspension can handle the weight I need to haul (about 3400 lbs) and tow the heavy trailers I have (2100 lbs empty). I also read that the pre-73 trucks have better frames. Is this true?

Where can I find a GMC master parts catalog in PDF format?

Not an assembly manual but an actual parts manual for 67-72 trucks.

[lizziemeister'sV6]

Been on this road before myself and friends of mine. First thing I would do is look at your State's Motor Vechicle guide lines on GVWs. If the GVW is over 26,000 pounds ( an example ) you may need - different operators license, commerical insurance (farm trucks rules vary) and higher road license plate tax based on the tonnage. This is a problem with older grain trucks that have a beautiful cab/body and would make a easy swap onto a smaller tonnage frame. But the VIN# on the Title/ and Plate on the cab tells the WHOLE story at the Courthouse DOT Office. You could change the VIN Plate on the cab but the title has its VIN # - I WOULDN'T EVEN think of messing with any alterations to either. Just walk away. Just do your homework before you make any decisions.