ok, so I need some knowlegable advice. I have a 1980 motor non- H.O. in my Mazda rx-7. It is bone stock except for headers and a 650 c.f.m edelbrock carb. I recently rebuilt the bottom end but didn't do the heads. Before I had a 1985 H.O. 302 i got from the wreckers in there, but after i put it in i found out it was in very bad shape so had to get this 1980 engine to replace it. I am finding a lack of power and i was thinking of refreshing the ho heads and putting on an edelbrock performer intake and a street cam. Then later when the budget permits i was gonna get some pro comp aluminum heads (2.02/1.60 175 intake ) on. My question is what would it take to make my 1980 a roller cam like my h.o. and are the h.o. heads interchangeable with my heads for the 1980 motor. thx for any help