Well since your boost wont be dropping off in the high Rpm's anymore, if you tune the car you'll prob still make a 332 or close figure.... least thats my bet.. I think with the old manifold if it wasnt broke and you held 19 lbs boost all the way to redline you woulda made 350..... so - 20 HP from going back to OK stock manifold = 330.. thats my educated guess