The rear cross bar on the frame is trashed from the idiots wrapping chains around it. My question is would it be easier to just fabricate something, or is it something I could find off any older Chevy? (it is a 71' Chevelle frame) I assume its not a refab part available online... also, some of the body mounts where the bolts go through to tie in to frame have rusted out. My idea is just to weld some 1/8" or so steel square plates at every mounting point and redrill the necessary holes. Anyone done these repairs?

I found a good used rear crossmember for my 68 and welded it in. 68-72 a-body are the same.

You mean the caged nuts are rusted out or the bolts themselves? You can get new body mounts and bolts.

On the actual body. The front ones at firewall area, left side is good, has your 1/2" or so hole to put bolt through, and on the right side, the hole has rusted out to about 3 inches...

KoDe,
You should be able to find a donor rear cross brace. Send John Watts a note www.johnwatts@diodecom.net . He's provided many here critical parts needed. Check out posts by Allyears.

On the frame mounts, you can trace the opposite side good mounts on paper, using the pattern to make replacement steel. Cut out the rusted area and weld in the replacement steel.

The rear frame crossmembr you would be better getting from a doner frame.The bodybushing mounting holes can be repaired.i cutout the rusted goles and fabricated new steel to weld in.Somepeople just weld the correct size washer(1 3/8" id.)but I opted to cut out the frame and weld mine flush.I hopefully will be getting back to it this weekend but some of the repair pictures are on my photo link.