This firewall fits all 30/31 passenger cars and pick-ups. This is a 2-piece firewall that when welded in place, makes a flat firewall with no set-back. This will give you approximately 2.5" more back space than your stock firewall. It will work well with flathead and V6 engines. It is made in 2 pieces to allow you to use the stock gas tank. The bottom edge is made to trim to your floor or a Direct Sheetmetal floor.