Campbell lists the 2315s at $620 per set. That's spittin' close to a decent "custom forged" piston.

The Diamonds that are the same as the 2315s except with valve pockets and weigh 100 grams less are $766.

The Keith Black pistons that JohnRR loves to hate because they've got extra huge valve pockets are more like $344, but they also have about stock weight. They'd get you to 9:1.

I think I'd use the KBs and put any savings into a hydraulic roller cam.

R.