ZZ502 Engine

Umm. So I'm new here... and new to this whole car thing in general. So bare with me.
I've got a ZZ502 motor bored 30 thousandths over to a 509. I want to replace the pistons in it to achieve a lower compression ratio, specifically a CR of 9:1. The CR right now is 13:1.

bore: 4.500"
stroke: 4.000"
rod: 6.135"
piston to deck: 0.015"
piston dome volume: -13.6 c.c.
combustion chamber: 62.0 c.c.
head gasket thickness: 0.039"

so uhh... where should I look to buy new pistons? What company should I go with? What should I vary (i.e. piston dome volume, head gasket thickness, compression height, etc.)?

flat top will get 9.3 with a 119 cc head chamber flat top piston 3cc. were are you getting 62.0 cc for a big block head chamber ? head gasket felpro F1047 is .039 and 10.5 cc

yep---some wrong numbers on head CCs-------------