1979 GMC Cab Rear Floor Rust
 

I bought a 1979 GMC Stepside Pickup and after further investigation i'm finding out the rust in the floor is a lot more extensive than i had originally anticipated. I'm finding thinner spots than normal on various areas on the back side under the seat. I already know the rockers, floor pans, cab supports and mounting rails are going to have to be replaced but i'm having a hard time sourcing replacement panel for the hump under the seat where the frame mounts through the cab. Has anyone else found an issue to this problem area?

Re: 1979 GMC Cab Rear Floor Rust
 

Usually the patch panel pieces they sell are the common areas for rust, as far as the back of the cab area, I have only seen them rust there on trucks that are extremely rusty. In your part of the world, I think rockers/floors/cab corners etc are pretty much standard procedure, but anything past that I would consider a different cab.

Re: 1979 GMC Cab Rear Floor Rust
 

I think you're out of luck for that piece, but it shouldn't be to hard to find someone that could cut that section out of a parts truck and ship it to ya.

Re: 1979 GMC Cab Rear Floor Rust
 

Thank you for your input. I've thought of finding a parts truck and possibly sectioning out the rear half of floor and re-welding it in. Its been hard to find GM SWB trucks for cheep cheep in this area that are not already completely rusted out. The frame is in good shape and the step side is repairable last guy started restoring but ran out of interest. Next step is to find swap meats or junk yard that haven't already been picked clean.

Another thought was to just get some metal bent and weld in a custom hump for the seat and fabricate a new seat bracket to fit. Is that an option?

Re: 1979 GMC Cab Rear Floor Rust
 

That would be an option for sure. Maybe you could share a pic of the area you're talking about, It might help get some different options

Re: 1979 GMC Cab Rear Floor Rust
 

Here are a few pictures. It may not be as bad as i had originally thought. Perhaps a few patches welded in instead of the whole rear floor? Main problem is panel that holds nut for seat mounting bolts.