It is not unusual for heads to be damm tight to get off. Unless there is something funny going on with the steel studs and the aluminum heads, it is probably just the gaskets and their "printoseal" type adhesive sticking. I understand you worry about those high dollar heads, but it would seem you could do a little prying in the valley area using wood as a guard against nicking the heads. A 2x in the valley, and a 1x under a portion of the head with a cheater bar between, you should be able to exert enough pressure to pop them loose. It would be a little messy, but you could also fill a cylinder with light oil and turn the motor over by hand to hydrolic the head up, (plug in, valves closed)....I've had some tough ones, but never had to worry about high dollar heads and just pried them off.......I would worry more about the torch method, than the pry method.............Good luck, MP