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

[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]

Originally Posted by 68crackerbox

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]

Originally Posted by 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.

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, 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

[TJ's GMC]

Originally Posted by George Bongert

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]

Originally Posted by 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.

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

[TJ's GMC]

Originally Posted by POWERSTROKE

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!