Combination change, what would i gain?

Yep Justin.
Last outing the car ran 7.23
4 times in a row. Had a long wait till the next round because of funny car and jet show, put a 22 on it and it ran 22, went red that round.Shift it at 6200
Your right, with the smallish heads( i suspect they might peak at 275/280 ish at 600) and small headers the 418 will probably like 6k. Nice long happy life.
Will have lots more compression, should 60 much better.