Hi All. New here. I've two questions about my '83 block and exhaust fitment to the early '78 head. One is, I just bought an exhaust gasket for the 20R & the 22R (I still stammer when buying parts). There's a big difference in circumference. Do people usually get a new exhaust system for their hybrid mods? One that better matches their exhaust manifold.
The other question is, my compression is 180 across the board, with #3 being 185. So I'm running with Ethyl (the pricey gasoline). I've a thicker head gasket, but I've also heard of people putting in two head gaskets to bring the compression down. Anyone know what the trick is here?