Re: 1/2 Ton vs. 3/4 Ton
 

When they took away the carb.

Re: 1/2 Ton vs. 3/4 Ton
 

Sorry. What I ment to say was. When they still had a carb.

Re: 1/2 Ton vs. 3/4 Ton
 

Yes they are... Just look for the part numbers stamped in the frame rail, same number, same frame. 1/2 and 3/4 4x2 = same frame, 1/2 and 3/4 4x4 = same frame. The actual 'rails' are the same, just the hole punch is different and then stamped with different number. 1 ton frames are thicker thickness and taller hieght wise under the cab and front of bed.

FYI... Depending on what the factory was short/long with, it is not uncommon to see a 4x4 frame under a 4x2... I've seen that at least 5 frames 73-86 (never saw an 87-91...) that were under a 4x2 truck that had all the holes punched for the 4x4 hangers for the front axle. I was able to vin match 3 of the trucks and verified frame match.

BTW While we are on frames... After US production ended of the 91 R/V body style, GM (who still needed to produce and store replacmenet frames) began putting frames in boxes unassembled. Thats right unassembled. They did that because the frames stored and shipped easier. (My opinon is they were importing the frames from Mexico, but I was unable to verify that.) Anyway, the instructions stated to assemble the frame with grade 8 hardware.

Re: 1/2 Ton vs. 3/4 Ton
 

X2
Some frames maybe thicker but it's more to do with inconsistencies in the thickness of the metal. They were all stamped from the same machine (or machines). The K20 I just sold had the same frame thickness as the K10 I have now. I parted out a K10 a few years ago that had a frame that was a bit thicker then my K20. 1/32 of and inch isn't a design difference, it's an inconsistency.

Re: 1/2 Ton vs. 3/4 Ton
 

I just pulled up my 1985 Chevy Truck Vehicle Information Kit downloaded from the GM Heritage Center found here:

http://www.gmheritagecenter.com/gm-h...tion-kits.html

It is a great publication for finding factory design data for my truck.

It lists the following frame section modulus for the 1985 model year.

C10 - 3.10
C20 6-Lug - 3.57
C20 8-Lug - 4.53
C20 Bonus Cab - 7.33
C30 - 6.14
C30 Bonus Cab - 7.33

K10 Short Bed - 3.14
K10 Long Bed - 3.88
K20 6-Lug - 3.88
K20 8-Lug - 4.53
K30 - 6.14
K30 Bonus Cab - 7.33

It also lists these trucks by Curb Weight:
(I've Listed All with Base Engine)

C10 Short Bed - 3486
C10 Long Bed - 3648
C20 6-Lug - 4048
C20 8-Lug - 4146
C20 Bonus Cab - 4747
C30 - 4409
C30 Bonus Cab - 4829

K10 Short Bed - 4048
K10 Long Bed - 4242
K20 6-Lug - 4489
K20 8-Lug - 4578
K30 - 4892
K30 Bonus Cab - 5308

Re: 1/2 Ton vs. 3/4 Ton
 

And I'll repeat, no. I've seen the GM spec sheets that list the different thicknesses. Also, not all year frames are stamped the same for 2x4 and 4x4. I've seen some conversions that the rail needs notched a bit for shackle clearance, for example.

Re: 1/2 Ton vs. 3/4 Ton
 

Is this what y'all are talking about? http://67-72chevytrucks.com/vboard/s...d.php?t=382332

Re: 1/2 Ton vs. 3/4 Ton
 

Yes thanks, that's one of them. There's other charts that are easier to follow, with body descriptions along with the model numbers, rather than just model numbers.

Re: 1/2 Ton vs. 3/4 Ton
 

So when I read that the k10903 longbox (131.5) has a frame thickness of .192 and the k20903 (131.5) longbox has a frame thickness of .192, hmm seems similar to me!
Yes the k20903/c6p (camper special) is thicker, but I'm talking about the difference between a standard 3/4 ton and 1/2 ton truck.

Re: 1/2 Ton vs. 3/4 Ton
 

Dude, what's your deal? That chart shows differences between other frames. And like I said before, not every year was the same. Good grief.

Re: 1/2 Ton vs. 3/4 Ton
 

I'm sorry to start an arguement. The thread is about Car'n'Guitars decision. I'd say look at the time you have to have your truck down, weigh the differance in how much work and money you want to put in, and go from there.

Re: 1/2 Ton vs. 3/4 Ton
 

Whats my deal? I say they are the same, you say I'm wrong then show me a chart that shows they are the same, and I'm the one with a deal, Whatever dude, Moving on!

Re: 1/2 Ton vs. 3/4 Ton
 

Yeah, because you are wrong. Hooray, you found one of the instances where the rails are the same thickness! Good job, well done! I applaud you!

...Now look over the rest of the chart one more time, that is unless you just refuse to be corrected. And I'll remind you one last time, the thicknesses varied from year to year.


Since when does most everyone here think that they are posting at pirate4x4 or s10forum?

Re: 1/2 Ton vs. 3/4 Ton
 

Wow you are dense aren't you! I'm not, nor was I ever talking about all the models of trucks listed in that spec sheet. When I said the frames are the same, Now try and follow me here, I was referring to the K10 long box and K20 long box frames which ARE identical. I'm not talking about the K5, or the short box, or the crew cabs, or even the s10's listed. Just those two trucks. Because they don't make 3/4 ton versions of for the k5, s10, or short box, and they don't make 1/2 ton versions of the crew cabs. As for the suburban, the frames are different anyway. Now you can go on being butt hurt over this argument, or you can move on like me.

MOVING ON!

Re: 1/2 Ton vs. 3/4 Ton
 

Anyone will sound butt hurt when they have to respond to snippy sounding posts like this:

Just because we don't agree, doesn't mean we can't discuss things and come to a conclusion. We don't all know everything, but someone is sure to learn something with a civil discussion. Now having said that, I would like to try this again.

First of all, I understand now that you were only considering one body style of truck and your focus ended there (which makes sense because that's the body style of truck that began this post). However, other folks may take this and assume that all frames are the same, especially because someone else stated that 2wd frames are also the same. If it gets left at that, misinformation is going to spread, and we all know that misinformation spreads like wildfire.

Now, in this case, the K10-K20 long bed frames are the same thickness, unless it's a camper special (which was stated by yourself). GM produced a lot of camper special equipped trucks, so it's really not correct to lump them all together and say they are the same since there's a lot of the thicker frames out there. Also, I'm 99.9% positive that other year K20s had a thicker frame (perhaps the same thickness as the camper special frame listed above?). There are spec sheets out there for other model years too, maybe I can find them again.

Finally, the other body styles. There are several different frame rail thicknesses that were used, depending on C10, K10, C20, K20, etc. Also, while the 2wd/4x4 frames often appear identical other than stamped holes, they just aren't the same. Thickness aside, every one I've ever seen has been a specific stamping for 2wd or 4x4. Engine cross members often don't swap, and the rails often need clearanced for the shackles.

Thoughts, comments?

Re: 1/2 Ton vs. 3/4 Ton
 

I have a 1968 C10 Panel and a 1968 C20 Long Bed. I measured both frames thicknesses with a micrometer.

C10 frame = 0.165 frame thickness
C20 frame = 0.200 frame thickness

Re: 1/2 Ton vs. 3/4 Ton
 

Ive got over a hundred chevy trucks. all kinds sizes & types. And in almost every instance the 3/4 ton frames are thicker Than a 1/2 ton. the one exception is the 60 thru 62 trucks that have the torsion bar front suspension. those frames have a large X member and the front and rear portions of the frame are boxed.

Re: 1/2 Ton vs. 3/4 Ton
 

Old Truck Man: I was just wondering so I measured my trucks for my own edification. I also saw the trailing arm reinforcement plates on the C20 which my C10 does not have.

poway

Re: 1/2 Ton vs. 3/4 Ton
 

forgot another weight difference th400 vs the 700 or th350