Originally Posted by zipper06

IMO, you are losing atleast 2 points in the compression, with the open chamber heads. I think the easiest way out would be to change to some 13.1 open chamber pistons. i don't know how much you would pick up but i would think close to 2 to 3ths. ofcourse you would have to rebalance the engine with these changes.

JMO

Zip.