340 questions - anybody recognize these pistons?

there seems to be a mismatch of pistons in your engine. the 3 ones on the left seem to be CAST sealed power z428 hi compression pistons while the one on the right seems to be a stock low compression piston from 72-73 or a replacement for those engines. look at the valve notches to see the difference. weight is the same for both types so apart from the compression difference, both are interchangeable. the only way to know for sure is to measure the distance of the pistons from the deck at top dead center. if im right ,the 3 ones on the left should come out of the deck about .007 inches at tdc ( 1.829 compression height) while the other one would be about .082 down in the hole at tdc ( 1.740 comp. height). this is only by judging pictures so i may be wrong, measure to be sure.