RE: Firewall thickness
Yeah, Scooter didn't elaborate on it, but if you drill some 1/16 holes through the fuse into the firewall, cut some 1/16 wire or threaded stock, slap some epoxy on the wire and slip into the holes. Cover with your favorite covering and nobody will ever know they are there. Also like GrayBeard says, if you put some triangle stock behind the firewall with the pins, you can put a Chevy 350 on the front of this thing if you want to and it ain't coming off.