Just o-ring ure head and make sure that the head and top of cylinder are decked and you will be good with the step studs. But to answer your ? i dont think you can especially if it is already o-ringed i have a friend that tryed drilling out a 87 cool head for 10mm and ended up ruining it but it was cut for orings the bigger holes collapsed into the o-ring grooves. Maybe we can get something like arp studs made for the small reeds?  I use these in my turbo talon it was stretching head bolts when i cranked it up over 6 psi now i can run 20-25 wit the arps and they are rediculous how tough they are.