68 dart with running 383 auto - advice to build another motor

Stock 383 high comp pistons were flat tops. The KB hypers we ran in my son's 383 were domed and had valve reliefs. We ran a cam in the .490" 230 @ .050 range. I've got the .484/284 cam in my 440 and we're putting a Comp in my other son's 440 (actually already in the motor - yesterday) that is 274/286, .488/.491. Should run good. He's got a four speed with 3.23s, I've got a 727 with 3.55s. Not sure which I will like better. He's got more compression than I do.