I've had ALOT of learning experiences so far.
After porting and installing bigger valves and trying alot of different combinations, here's what worked the best. lightly pocket port the exhaust port and install 1.60 exh valves. Back cut the intake valves. If you mill the heads more than .015 and install .015-.020 head gaskets, you'll have to use legnthened push rods (+ .100 I think) Other rules are: No standard dampers can be used. Buy the springs from Comp Cams or Crane for LT-1 heads for .500 lift. DON'T use regular springs with dampers. Also the spring seats are machined for BIGGER than stock springs. We have used 1.44 springs w/o dampers without problems.Also, if you plan to use the GM valve cover adaptors, you can't run the "stepped up" type of push rod guides. Use the Isky flat types if you are going to use screw in studs which are highly recommended for any cam with lift of over .500. You can safely go to .600 lift even with milled heads and flat top pistons. No worry there. Um....can't think of anything else right now. Good Luck!