I spoke with a Tech at JE/SRP about 502 pistons for standard deck and 6.135 rod

123475= Similar to GM OE w/high silicate (low expansion), 1cc closed chamber, 8.8 w/118cc head, 5/64 rings, 4.468 bore, .0040 to .0045 clearance cold water application, list $548

123189= 4cc open chamber, 9.2 w/118cc head,1/16 ring, 4.469 Bore, .0050 to .0055 cold water application, "more durable" list $717

SpeedPro also offers a forged 4.500 piston for a 6.135 rod.

Rick R, give me a call and I am pretty sure I can direct you to a better price on pistons than what you have listed there. Mark 616-291-7932