alright i have been searching around and cant find the answer. i have 64.4cc 243 cylinder heads that i had ported and polished and what not. now i am going to be running nitrous very soon. the engines apart because i had the heads flowed so i can order a custom cam. now my compression ratio at this present time is 10.4:1. i am thinking of spraying anywhere from a 150-300 kit. now the camshaft guy said i could mill the heads but not to much as i could warp the decks. what is considered too much? i would like the added compression and this is a weekend warrior so no worries there.

anybody know what i am talking about or can give me a suggestion as to find out how to calculate it? the amount i can mill also had to do with how much pvc i have which i need to measure that when the cam comes in.