Well,I have the same Aussie Intake you have,and you're saying that Boost isn't good with that one I'll just stick with the original build intentions and go for NA compression ! Again I won't know everything I need 'till I get my head from Frank,and the block taken apart once it's out ! A 54cc head should give me 10.6/1,then depending on where it sits in the block will help me with the other decisions !! Yes,as stated I have have Main studs and Head studs,don't think I'll be taking it far enough to have to worry about O ringing at all ! Just going to play it by ear,nothing set in stone !! I was more than pleased with my last build,so this will just be a step or 2 or 3 or ...more ??