My 70 Malibu build

[shadowgray396]

You have 2 items that go behind the seat. The Trunk divider and the insulation.
http://www.ss396.com/category/chevel...nkdivider.html

Some do just use the fatmat or other material back there.

I had my frame sand blasted, cost about $75 when I had it done. But I also had it powder coated so that was the only way to go.