Im not tring to come on as a know it all, but I can tell just by looking at this post that people are tring to defend an engine that wasn't truely ment to be all out modded. Sure people make good power on it, people make good power on V-8's too if you wish to distrub the weight balance that much I advised a nice LT-1 or 350. With a blower you could make well into the 700hp range!
p/s
Cars that are PITA and have blown headgaskets all the time are not fun