THE absolute best port job on a set of iron heads will cost you more than a set of TA aluminum heads and that is where the TA heads start to flow before you do any porting on them. Unless someone gives you ported iron heads, don't waste your money making iron heads flow. The only reason to do that is some class-specific racing.
Thermodynamically if each head was ported the same and the compression the same the iron ones would make more power.
But to answer your question somewhat,..theres too many variables to consider,..but given the same engine 464~482 10.0 compression 240-250 cam with say decent ported irons and all the bolt ons,..single plane intake,..525hp,...with box stock aluminum heads,..600,....with mild port work 630ish Stock irons on same engine $1200ish for rebuilt heads,...485ish mayybbee,....ported irons $3200ish TA aluminums $3200 now will be 4k soon I'm sure,...and not available with no real eta,....so theres your choices
I had some valve work done for around $500. Then just ported the exhaust myself to the gasket. But yea I want aluminum heads sometime time the road. I'm fine running 12.60's
my 73 stage heads got a single scallop plugged, each head, so they could be run on earlier blocks, milled the minimum to flatten all three surfaces, substantial bowl work and port matched, guides cut for dual springs, 1k. There was 500 more in parts, dual springs, stainless valves, retainers and locks. So for 1500, if you have some factory stage 1 heads, you are off to the races. They make a bunch of torque and a bunch more with power adders. Key is big solid split duration cam with emphasis on exhaust
But remember....there is porting and there is real pocket porting that makes the HP. And....validated on flow bench.
