the comperssion is 11:9:1 comperssion. on a 64 cc head. and sorry i made a gave the wrong price.. i want $200 for everything. i had my friend post it up a while ago and for some reason he put 130.. i paid $260 for the pistons and $60 for the arp rod bolts and $150 in the rods. thats a total of $470.. im only wanting 200 for them.. if your still interested ill send you pics.. i also have a big cam for a sbc too that im selling .. .555/.555 lift and 306/306 duration. for for $80 brand new still in the box.