Steve, it looks to me like you've already answered your own question. The 882's with those big ol' 76cc chambers are gonna keep your compression below 9-1. Not the way to make 325hp but not impossible. I have learned the hard way the way to power is a good set of heads. The GM vortec heads (54cc) will increase your compression, make gobs of torque and pull like a bandit through 5500-6000 rpm's. 'bout $350 ea.

BUT, why not go ahead and pony up and get a nice set of Canfield aluminum w/195 cc intake runners? Last ya' a lifetime for the lowly price of $1200 a pair .