I'm restoring a 71 Chevelle Malibu and I have done the front floor pans, used whole floor pans went in very nice.
Now I need some help the body to frame mount that runs over the rear wheels is rotted out on both sides and I need to fin a new one can you buy this piece.

The two braces that are above the gas tank?
I just got one from Goodmark.

no it's the brace that go's right acrossed the back seat and there is two body mounts that go there.