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Old 03-20-2017, 07:39 PM   #1
interceptor78
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Question new here need help please
so I bought my first square body today question I need a frame what years or trucks will work or inter change with little mod same go's for rad support inner fenders and cab thanks' for the help truck is a 83 gmc c30 dully dump truck

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Old 03-20-2017, 09:52 PM   #2
 
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I would think the best frame candidate is a 1981-87 C30 complete chassis if it's a standard cab. 1981-91 if it's a crew cab.

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Old 03-20-2017, 10:45 PM   #3
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it is a reg cab thank you what about the rad support cab and inter fenders what truck and years inter change?
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Old 03-20-2017, 11:32 PM   #4
 
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Originally Posted by interceptor78 View Post
it is a reg cab thank you what about the rad support cab and inter fenders what truck and years inter change?
In yours, you'll need an '81-'88 quad headlight core support if that's what you have or an '81-'88 single headlight core support if that's what you have. A correct core support from a 1988 vehicle will come off a Suburban, Blazer/Jimmy, or crew cab and pickup trucks for all the other years. Inner fenders will interchange between a 1981-1991 square body.
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Old 03-21-2017, 09:38 AM   #5
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Default will this work ??
I found a 85 chevy c30 one ton truck but it is a single wheel truck rears might be diff but I have a good rear frame should work?? rest of the parts will thanks for the help so far
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Old 03-21-2017, 10:44 AM   #6
 
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post up some pictures of what you have and it will be easier for us to advise you. Are you intending on keeping the dump bed? If so, how long is the dump bed? Do you want to convert to 4x4? If you are going to basically get an all new truck other than the bed, i woud advise to find a c&c truck that is close to what you want and swap the bed, that way all your vins line up and what not.


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Old 03-21-2017, 12:17 PM   #7
 
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One other possibility here too, is was the truck originally a cab an chassis truck before the dump bed was installed? I know those frames were a little longer than a standard pick-up, and there may be a difference in frame width also. I'm not 100% on that though.
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Old 03-21-2017, 01:01 PM   #8
 
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Very true. The VIN will have to be cited on whether it was a chassis cab or not.
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Old 03-21-2017, 09:56 PM   #9
 
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i don't believe the frame widths were different but the rear frame of a cab and chassis is flat i believe with no hump for the rear axle.


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Old 03-21-2017, 10:42 PM   #10
 
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Originally Posted by 1987 GMC Jimmy View Post
Very true. The VIN will have to be cited on whether it was a chassis cab or not.
Crap. Forget all of that. I forgot that the newer VIN's don't tell you if it's a chassis cab. It did on the Action Lines and the squares up to '80, I think. Check for an RPO code ZW9. That's the only one I could find affiliated with chassis cab/pickup box delete.
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Old 03-22-2017, 05:22 AM   #11
 
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Originally Posted by 87silveradok20 View Post
i don't believe the frame widths were different but the rear frame of a cab and chassis is flat i believe with no hump for the rear axle.
I can't recall frame differences exactly, but I do know there was something different on the rear axles, either with spring pearch spacing or overall width.
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Old 03-23-2017, 07:48 AM   #12
 
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Originally Posted by CSFJ View Post
I can't recall frame differences exactly, but I do know there was something different on the rear axles, either with spring pearch spacing or overall width.
The rear axles themselves are skinnier for a c&c dually. They are actually skinnier than a single wheel rear end.


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Old 03-23-2017, 08:44 AM   #13
 
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Originally Posted by 87silveradok20 View Post
The rear axles themselves are skinnier for a c&c dually. They are actually skinnier than a single wheel rear end.
I'm not sure if that's totally true. I had an '87 CC dually. The rear inner tires tracked with the front tires. The rears stuck out the width of the tire and wheel assembly. I have seen dually tow trucks and dump trucks with a narrowed rear ends similar to the pictures below. The last picture is what it looks like with one of those rear ends under a standard fleetside bed.





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Old 03-23-2017, 09:10 AM   #14
 
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Originally Posted by Craig 85 View Post
I'm not sure if that's totally true. I had an '87 CC dually. The rear inner tires tracked with the front tires. The rears stuck out the width of the tire and wheel assembly. I have seen dually tow trucks and dump trucks with a narrowed rear ends similar to the pictures below. The last picture is what it looks like with one of those rear ends under a standard fleetside bed.
Yes you are correct, "dually" rear ends are the same as single wheel and the outer wheel sticks out, tow truck type are narrower, if you draw a line from the center of the front tire to the back, the line will be directly in center between the two tires, friend of mine converted his C20 to a dually and used a rear end from a dump truck(it was free)and it looked funny when it was done, so we put his beside my dually and started measuring and backing plate to backing plate was narrower on his(don't remember the numbers now been a long time) and his front wheels were in the center of his rear wheels.


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Old 03-23-2017, 08:19 PM   #15
 
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Originally Posted by Craig 85 View Post
I'm not sure if that's totally true. I had an '87 CC dually. The rear inner tires tracked with the front tires. The rears stuck out the width of the tire and wheel assembly. I have seen dually tow trucks and dump trucks with a narrowed rear ends similar to the pictures below. The last picture is what it looks like with one of those rear ends under a standard fleetside bed.



I guess i shouldve put it this way. A 14 bt dually axle is skinnier than a 14 bt single wheel and a dana 70 is wider than a single wheel 14 bt (I think). The 14 bt dually is what is most commonly found in c&c trucks


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