ok, I have no real experience with 6leakers, but imo, if the hg are holding right now, and you realize that you may still have to pull the heads in the future, the only thing your really risking is your time. if the gaskets are sealed up right now and you do one at a time, there is no pressure on them, I'd take each stud to 50-75% percent of final value until they are all in and then follow procedure from there. I'm guessing that the studs use a much higher final torque value than factory bolts- if so it doesn't make sense to take them all they way on the first pass- you would want to only go to factory spec initially . Anyway I'm interested to see how this turns out.