Quote Originally Posted by zackmx
well would it be worth doing it if i had a rv cam long tube hedders 670 street avenger electric fan "i dunno if that really does anything" and if im donna do it do i have to take out the valves?
It's worth some Hp and efficiancy - but like I said, without a before and after dyno test - who knows. 5, 10 or....??

You should disassemble the heads - you scatter metal chips all over everthing in sight when you grind.

While you have the heads apart, you might as well install 3/8" screw in rocker studs. Easy job - pull out the OEM press in studs, tap with qualitynew and sharp 7/16" taps, starting with a taper and finishing with a plug or bottoming tap(the stud hole is already the right size), then screw in place with some Loc-Tite.