03 CR compression

I'm thinking about milling my head and switching to race gas to see if i can get better throttle response out of my bike. I think the stock compression is 8.5:1. I'm at 4500' and i'm sure this doesn't help either. The troubble is that i don't know how much to take off as i don't want to much compression either. Is there anyone who has done this? How much did you have taken off? Before doing any work to the head i wouldn't mind even just trying a thinner head gasket. I don't want to go to straight race fuel, but would could stand to go 50-50 race - pump. If thinner gaskets are available, who makes them, and would a thinner gasket really make that much of a difference?If anyone has any ideas how to aproach this i would sure appreciate it

03 CR Head volume

Can someone tell me what the volume of my stock 03 CR head is in cc's. I want to deck my head and need to figure out how much to take off.

Could i send you a new head and have you make the necessary modifications to it as well as shave it to run race fuel? I would prefer to have a seperate high compression head for it anyway so the new owner has the two options. I know your buisy right now and probly don't have time. When will you be in your new shop taking more work orders?