you may or may not max them out. what's feeding them? if you've got a good fuel pump that may be a different scenario. when you say 3.92 are you talking Psi or Kpa? the thing you're going to have to worry about most is the block holding up. 750 should be more than enough, but i think some 550's with proper fuel management should be fine under 11psi. any more than that and kiss your ring lands goodbye.