ls1blown871

I need a set of 317 casting heads (71 cc). I have been looking at Ebay
and they two different exhaust port shape for the same casting number.
Need help. Why are there two different ports (one "D" shape,the other
round shape) with the same casting number. Also does anybody know
if you can get into the 8's with a thicker gasket with these heads???

BigTex

iTrader: (16)

All 317 castings will have D shaped exhaust ports. If you saw a round port, it was likely not a 317 head, or it was ported to a different shape.

ls1blown871

THANKS FOR THE REPLY.
Does anyone know if you can get under 9.1 compression with these heads without changing the pistons. Maybe take some "CC" out of the heads?????