who makes MP forged pistons?

off the top you can run a larger cam lift, but that really depends on the shape of the dome. Even the low-po 318 pistons have valve reliefs.

I only ask because i noticed the cheaper sealed power pistons (cheaper than the icons, about 350 for the set) are flat tops with no valve releifs...the Icons that 70AAR listed do have valve releifs, so depending on my goals (not totally certain, still learning and planning as i go along) the Icon's may be the ticket for me