How many cc's will flycutting take out of pistons?

[Vibrant93]

I am in the process of building an NA 347 and am running into a few delema situations. First off the car will have afr 205 heads which have 2.08 intake valves in them. Secondly I want to keep compression up in the 11.2:1 range and am finding that this is going to be a problem. The lightweight srp flat top pistions that I got have only 3cc reliefs in them which I assume will not be enough for any decent size cam and the 2.08" valves. Assuming I have the block set up with a zero deck and an 8548-pt2 head gasket this puts me at 11.278 with .020" taken off the afrs to bring them down to a 56cc chamber. So what I am wondering is about how many cc's on average does flycutting take out of a piston? I figure I may just have to use a thiner 1011-2 head gasket and or bring the piston .010" out of the hole. Am I going in the right direction here or are people running the afr 205's finding that they arent needing as big of valve reliefs as they thought they needed? Thanks for any input!