Help needed with frame to cab mount brackets 69 cab on 65 frame
 

http://i327.photobucket.com/albums/k...pscd7c8a6c.jpg

I have been working on a custom frame for my 69 GMC short bed that you can see in my build thread in my signature. the frame that I've used is a 1965 c10 short bed. I was told the frames were the same 62-72 and they appear to be the same with only slight differences.
Anyways I have determined one of these differences is the rear cab mount bracket, which seems to be an inch taller than the one used on the 69. I had a spare frame from a 68 which we had previously cut up and i have the section where the rear cab mount bracket normally is plug welded to.
the problem that I am encountering now is that none of the holes seem to line up. There is a big hole that I believe to be a positioning hole. my question is do I use this hole to center my 69 cab mount bracket? here are some pics. Any insight with this is apreciated.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

I am having difficulty accesing my photobucket right now so cant post the other picture but when overlapped none of the bolt holes line up when centered on the big alignment hole.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

I will try again later to get the picture up.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

Bump.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

So basicly what I am trying to figure out is if the larger hole in the center is in the same location on the early frame as the 67-72. If so then this will solve my problem.

Correct me if I am wrong but I believe the front mount brackets are the same and in the same location on both generations.

I need to sleeve the hole needed for the mount bracket in the boxed in section of the frame before I plate the inside.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

I'm sure you've attempted something like this, but is there something on both frames that you KNOW is the same? Use that as a reference point and measure to your hole.

(Sorry if that is completely impossible. I've never done something like what your doing, just seems plausible.)

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

Unfortunately, imo you are on your own on this one. Probably not too many folks have a "backdated" frame swap. Good luck, sorry i cant help.

Re: Help needed with frame to cab mount brackets 69 cab on 65 frame
 

I have another frame to measure of off but its currently in use, and a little more difficult to measure being that the holes are still plug welded and the mount brackets are in the way . I might be able to make some sort of jig to measure the dottom holes from front to back, being I am pretty sure the front holes are in the same location on both frames.

I am building this frame on the side until its ready for the 69 body/cab swap. I want my truck to be mobile as long as it can be.