79 to 77 frame conversion

[Michael B.]

After a long very long (unintended) break I'm back to restoring my wifes 77.

Here's what is hopefully a simple question to the experts.

When I purchased the original donor frame and restored it (sand blasted, repainted, stamped serial numbers) I had not yet taken the body off the old frame completely so I did not realize I had been sold a 79 frame.

The one major difference I see is the rear frame brace, where the gas tank straps onto. After looking at many options it seems to me it makes the most sense chisel/cut off the 2 rear frame cross members off and place the original on the restored 79 frame. The rear cross member just seems to attach flush to the bumper bolt flange, so no adjustments should be required.

I've measured the distances from the body mounts to the where the rear bumper bolts go and they seem to be the same give or take 1/8". Shimming should be all that is required.

Could anyone comment if I a missing something critical.

Thanks for the help,

Michael B.

[Harmon C.]

Re: 79 to 77 frame conversion

Michael
A Chisel/cut? Time to buy a Metabo 6" slicer cutting tool. This unit has a clutch to keep from blowing up the .040 thick wheels. This tool will become your best friend in any shop. Will make clean cuts for removal and instalation.

Lyle

[Michael B.]

Re: 79 to 77 frame conversion

Hi Lyle,

Thank for the input. I'm always looking for the "next" shop tool. I could not find this in their product catalogue however. Is there another name for it or catalogue number.

BUT, to the point I was trying to get to, is the method correct? Will the removel of the rear frame crossmember and replacing directly with the 77 crossmember (to strap the gas tank onto properly) effectively make this a 77 frame??? Measurements tell me it will.

Thanks,

Michael B.

[Harmon C.]

Re: 79 to 77 frame conversion

I have not checked thease two years of frames. I would check the measurements from each frame and dive in. Try (Metabo) in a google search you should find many models but buy a 6" as the smaller 4" has a limited depth of cut.

Lyle

[Dick W.]

Re: 79 to 77 frame conversion

For the last few years that a service frame was available from GM it was the '82 frame. Like yours, just a few brackets, holes, etc had to be changed to make it work on earlier cars.

[Michael B.]

Re: 79 to 77 frame conversion

Hi Dick,

I greatly appreciate this response. I know I still have some holes to drill for the gas tank shield, and likely others I've forgotten about, but this is the very data I needed.

Cheers.

Michael B.