Frame rails - The 1947 - Present Chevrolet & GMC Truck Message Board Network

koolkat269 · 03-16-2015, 12:17 PM

Don't have time to look for it but was wondering if 2wd 1/2 ton frame rails are the same as 4wd 3/4 ton for the 80's model.

crashz · 03-16-2015, 04:30 PM

I don't think so.

There was a great post with a GM frame chart here, but I can't find it. Anyway it related GVWR and series with bending moment. There was a lot of factors, but mostly relating to section modulus, and for those series (as dimensions are basically the same for long bed rails) the thickness of the steel was the difference. There was some crossover, but very little. IE- its possible that a heavy 1/2 frame rail would be the same as a light duty 3/4 rail, but it would need to be referenced by serial number.

Slammed84 · 03-16-2015, 11:46 PM

Quote:

Originally Posted by crashz

I don't think so.

There was a great post with a GM frame chart here, but I can't find it. Anyway it related GVWR and series with bending moment. There was a lot of factors, but mostly relating to section modulus, and for those series (as dimensions are basically the same for long bed rails) the thickness of the steel was the difference. There was some crossover, but very little. IE- its possible that a heavy 1/2 frame rail would be the same as a light duty 3/4 rail, but it would need to be referenced by serial number.

So is that what a heavy half is? Just a beefier frame but 1/2 ton suspension? What is the Big 10?

andrewmp6 · 03-17-2015, 01:56 AM

The look a like but not sure on the frame thickness if that matter or not.Why do you ask?Is your frame rotted out or trying to do a 4x4 swap by swapping the bodies?

GM72K10 · 03-17-2015, 06:15 AM

Thickness is different

koolkat269 · 03-17-2015, 07:06 AM

Quote:

Originally Posted by andrewmp6

The look a like but not sure on the frame thickness if that matter or not.Why do you ask?Is your frame rotted out or trying to do a 4x4 swap by swapping the bodies?

Actually I have a 86 roller that I am using the suspension and rear-end in my 64 and a kid at work has a 3/4 ton 4x4 that has a cracked frame

Keith Seymore · 03-17-2015, 07:29 AM

Quote:

Originally Posted by Slammed84

So is that what a heavy half is? Just a beefier frame but 1/2 ton suspension? What is the Big 10?

Other way around.

Big 10/Heavy Half use the 1/2 ton frame but get heavier duty springs/leaf spring packs.

K

03-16-2015, 12:17 PM	#1
koolkat269 Registered User Join Date: Feb 2015 Location: Albion, Mich Posts: 20	Frame rails Don't have time to look for it but was wondering if 2wd 1/2 ton frame rails are the same as 4wd 3/4 ton for the 80's model.

03-16-2015, 04:30 PM	#2
crashz Registered User Join Date: Jul 2012 Location: MA Posts: 207	Re: Frame rails I don't think so. There was a great post with a GM frame chart here, but I can't find it. Anyway it related GVWR and series with bending moment. There was a lot of factors, but mostly relating to section modulus, and for those series (as dimensions are basically the same for long bed rails) the thickness of the steel was the difference. There was some crossover, but very little. IE- its possible that a heavy 1/2 frame rail would be the same as a light duty 3/4 rail, but it would need to be referenced by serial number. __________________ 2012 Chevy 2500HD, 6.0L, 6spd auto, 4x4, ECSB 1987 GMC V3500 Dump, 6.2L diesel, TH400 1983 GMC K2500 - awaiting its restoration and Cummins swap.

03-17-2015, 01:56 AM	#4
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: Frame rails The look a like but not sure on the frame thickness if that matter or not.Why do you ask?Is your frame rotted out or trying to do a 4x4 swap by swapping the bodies?

03-17-2015, 06:15 AM	#5
GM72K10 Next! Join Date: Jan 2003 Location: Eastern Pa. Posts: 2,483	Re: Frame rails Thickness is different Attached Images __________________ 86 K30 CUCV M1028A1 86 K30 CUCV M1028a2 dually 86 K30 C&C 6.2 4:56s, 4M, 11,000 gvw, ex fire truck, now lowboy dump More square bodies and CUCVs than I care to admit to 2020 Silverado K3500HD Work truck



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