Block Milling

Sounds like I will have enough compression with the mag heads. The pistons are Speed Pro H405CP-40. Campbell Racing web site shows them with 63 cc heads at 9:22 Compression. The compression distance is 1.637, and they are a flat top with four valve reliefs. It doesn't say how much the reliefs are. I have seen write ups that say the Mag heads are 59 cc"s but I really don't know. I didthe math and came up with 10:65 but I used 14 cc for the valve reliefs, so I am probably wrong. Anyway, thanks for the help