I've seen them shaved more than 50 thousandths, but I really need to ask Marlin for a professional answer.
I do know that a 20R has to be shaved approx. 160 thousandths to fit onto a 1985+ (short) 22R engine block, so maybe you can shave the crap out of a 22R head as well.
BTW, what year 22R head are we talking about?
Mike
