I have used one set of the KB forged pistons, probally sold under the Icon brand name now . they fit well, balanced well and performed well in the motor on the dyno. The motor is a BB 440 with a 3.91 stroke crankshaft bored to 4.380. I don't remember the part # but they where flat tops with two valve reliefs, using a set of B!-BS heads that had 59 CC chambers the motor had right at 13.0to 1 compression ratio, the motor made 720 HP at 7000 RPM and had not reached peak HP at that RPM This is a bracket motor and the owner was there and did not want to rev it past 7000 RPM, that is the reason for stopping the pulls at 7000 RPM. IHTHs, BTW I'm going to buy another set with a reverse dome for a street and strip motor with the same stroke and rod lengths asthe bracket motor, I'll be shooting for 10.5 to 1 comp. ratio for pump gas