aluminum heads

stroked 340 said
None,but if i absolutely have to i'd use x or j's...

I agree. X, J, then 308/596 heads. But factory iron only goes so far. OOTB Edel. heads are a great bang for the buck. But if you (The OE poster) has limited funds, stick with the iron heads like I said and just bowl port and back cut the OE valves.