Well, if its going to see a blower then I would leave the compression alone. If not, then .030 would be a safe bet on milling, but you may want to research your cams first. For example, the AFM N41 cam is designed for GT40 heads, but takes advantage of all the clearance available with stock pistons. Really doesn't leave much room for milling.
Joe
Joe
I've never driven one, so I can't really say. They recommend a 3.73 gear as minimum. I was told that it will buck a little at low speeds, but thats going to happen with alot of cams. It is lower on their list of cams as far as extremeties go.
Joe