Heads, how much gain?

Just be happy with what you have if you don’t have $3-5000 worth of play money to dump.... which it doesn’t sound like you do. Let the people who have play money chase every 50+ horsepower. The next guy will always have more time, $, and Hp anyway... not that there is anything wrong with that. Besides... you can’t just upgrade one thing. One upgrade always leads to complications up or downstream anyway. I totally get it, but just my .02.
I have welded up my ported 452s. 3rd time was enough. You can pay up front? Or pay later. Remember how old the cast is on those heads? Even if treated tame.