A lot depends on the heads to begin with. The last set of 452s I did I had more than 16 hours in. They flowed in the high 280s and 210 on the exh with 2.14 intakes and 1.81 exh. However, in order to get the seats ad guides in shape, plus trim downt eh guides for positive seals and cut the spring seats for dual springs, plus the milling to get the cc's reasonable and the milling to make the intake fit right after the deck milling... I could have had a set of out of the box RPMs. So, if you look at benefit vs cost, there is only a slight nod if any towards aluminum. If it was me, I would concentrate less on 2.18/1.88 valves and focus on new guides and smaller valves, and a shop that can cut the seats with modern equipment. A propoerly sized guide and new valve will make more power than a bigger valve and stone valve job or loose guides. Especially in the lift ranges you are talking. You can grind all day, or have the throat work done as part of a performance valve job. In any event, I think $900 including parts will not be able to get it done very well. And in regard to porting, Less is MORE.
