i have a rather strange question my buddy asked me if p74 (ls) pistons will fit in a b16 block to lower his compression for boost. the reason for this is that he has 2 b16 motors and i have an ls swap in my car. im buying his vtec head and im taking his pistons for the sweet *** compression and i told him he can have my pistons if theyll fit and work. so if anyone knows thanks alot.

 

they fit but why not just spend the extra $$$ and get pistons that are forged???

I mean its gonna cost money to put them in, might as well do pistons and rods

 

That would give you 8.5:1 per C-Speeds calculator. A bit low, but you could throw a **** ton of boost at it.
I second the 'just get new pistons/rods' and be done with it. But I dont know your budget/goals. If your on a serious budget, try scoring some used USDM ITR pistons for your B16. It will put you at 9.7:1, BUT the wrist-pin area needs to machined. I am up to 14psi on that setup.

 

is that too low or would it be allright im gonna do the piston swap so thats why were just gonna trade straight up and he is on kind of a tight budget. damn thats some low compression