Bring it on

If I read your first post correctly, you don't want to go with aluminum, I.E. aftermarket heads. To make what I would guess to be a 600 crank HP 440, you are going to need a really well thought out combo of intake, cylinder head flow, cam timing and exhaust. I am pretty sure by the time you prep a set of iron heads to reach that level, you would be money ahead with some aftermarket heads.