They look pressure cast to me? Anyway, the pistons aren't really the issue, I'd be worried about the 1800 rods and standard bolts if you want to up the power. Pistons should be fine
Yeah im gonna have to give that some thought, before it was stripped it had been running 16psi after a custom map by MSD.
Whats the options rod wise? Are the 1.8 rods a different length than 1.6 or is it made up by the throw of the crank?
Grant