ian08

hi guys i bought a 08z with ips stage 2 ported heads and it says the heads are milled to 70cc with stock gm head gaskets does anybody know how much this raises my compression thanks

427ZM

70cc is stock chamber size, so it's 11:1. Also, rule of thumb, .006 of milling = loss of 1cc chamber size.

ian08

oh okay thanks i thought the stock was like 71 or 72 must just be a clean up mill kinda confused why the would list that on there site

427ZM

From visiting their site it looks like they are just stating the stock chamber size and also showing that in that price milling to your desired spec is included. Just for FYI, 65cc (25 thou) would put you at roughly 11.5:1 and 64cc (30 thou) @ 11.6,7:1.

ian08

okay thanks i tried emailing them once no response guess ill have to call them and find out what they did to this car i would like to procharge it so i need to know if they milled or not