Well any alum head will kill your power , you only have 8.5:1 compression now & alum will cost you another point of compression bring you down to 7.5:1 effectively so you would need to get into the 10.5:1 with pistons before considering any Alum head . The better route would be to locate a set of the 516 or 915 closed chamber heads & get back into the 9.5 range , you could swap out the cam as well but my find you have good power with just the closed chamber heads properly ported , you will see a power gain moving to a Proform Carb , I would avoid the Demon carb , they are too Problematic