The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 702 GMC V-12 powered '62 GMC 1-ton

cayoterun · 11-20-2007, 11:36 AM

Got some questions:

#1: What's the highest ratio rear end gears available for Chevy 1 tons? I'd like to get up as high as 3 if possible.

#2: Would the '78? cab/chassis complete rear end be a direct swap out to the '91 dually FRAME? or is the frame widths different?

With a 2400rpm max on the v-12, I hope to use a 5spd overdrive tranny and increase the rearend ratio enough to get 80mph @2400.
I have a 3spd over auxillary tranny available, but would like to stay away from the extra driveshafts, length in the drive line, and keep the whole drive line as simple as possible.

It's for sure I have no worries about torque or power to pull high ratios, but need gears stout enough to stand a 20,000#max cgvw occasionally, so trying to stay with all 1 ton components.

Maybe, just maybe, this week we can fire the old motor, and then start the search for clutch/driveline. I want to have all that matched up and assembled in the shop floor before attempting to sit the package in a frame. I'm guessing all combined is going to weigh 2,000# or more.

Couldn't resist: My son noticed yesterday my dog (Scooter) would match my truck.
I guaroontee the pic hasn't been messed with, he's half Beagle and half mini-weenie. He had an encounter with a rattlesnake awhile back, (Rattlesnake won) but is ok now.

Enough trivia for today
Thanks,
Cayoterun

11-20-2007, 11:36 AM	#101
cayoterun Junior Member Join Date: Dec 2006 Location: Guymon, Oklahoma Posts: 2,040	Re: GMC V-12 powered '91 Chev crewcab Got some questions: #1: What's the highest ratio rear end gears available for Chevy 1 tons? I'd like to get up as high as 3 if possible. #2: Would the '78? cab/chassis complete rear end be a direct swap out to the '91 dually FRAME? or is the frame widths different? With a 2400rpm max on the v-12, I hope to use a 5spd overdrive tranny and increase the rearend ratio enough to get 80mph @2400. I have a 3spd over auxillary tranny available, but would like to stay away from the extra driveshafts, length in the drive line, and keep the whole drive line as simple as possible. It's for sure I have no worries about torque or power to pull high ratios, but need gears stout enough to stand a 20,000#max cgvw occasionally, so trying to stay with all 1 ton components. Maybe, just maybe, this week we can fire the old motor, and then start the search for clutch/driveline. I want to have all that matched up and assembled in the shop floor before attempting to sit the package in a frame. I'm guessing all combined is going to weigh 2,000# or more. Couldn't resist: My son noticed yesterday my dog (Scooter) would match my truck. I guaroontee the pic hasn't been messed with, he's half Beagle and half mini-weenie. He had an encounter with a rattlesnake awhile back, (Rattlesnake won) but is ok now. Enough trivia for today Thanks, Cayoterun Attached Images __________________ Cayoterun Okla. Panhandle I think I'll do it myself and pay the extra $500. Last edited by cayoterun; 11-20-2007 at 12:32 PM.