LA318 Pistons for performance build????

Thew 318 is hard to shop for in the piston area. Your not alone.
Federal-Mougal also makes pistons for the 318 in a cast Hyper-U. I do not know much about them though.
Your best bet is more likely the KB piston if the trick BJRracing dosen't fit the bill.
Performance wise, the Hyper-U piston is best for street to mild race. The froged piston is best for hard core builds.
The only thing to watch out for with a Hyper-U pistons is timing. You do NOT want it to ping (Detonation) at all!