There’s 25+ hp to be gained with a bigger cam........ but you’ll likely lose a bit of driveability to get it.

I dynoed a 505 last fall, rpm heads, about the same sized cam as yours....... made about 515hp.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads