Oh, if I go with aftermarket heads it will be aluminum. I think from what I looked at before, it would be like $700 for a set of the speedmaster aluminums setup for flat tappet (for the pair). I will only stay iron if I can find a cheaper set locally.
I think I mentioned it above, but I went out to the garage quick this morning to measure the valves, and they are indeed the 1.78/1.60.
The only iron heads I would purchase would be if I could find a reasonably priced factory casting with larger valves in them already. Otherwise I will look at aluminum aftermarket. Machine shop costs here are not cheap, so reworking factory heads is really not something in the budget unless I would be building a stock eliminator type deal where I had to use them.