That cam is pretty small, it has less duration than a 454 Magnum cam.
I have had good results in the past using roller rocker arms on 454's, they lower your oil temps and free up a couple hp.
You didnt mention an intake manifold, but I would use a Performer RPM or air gap manifold.
Bump up compression to around 9.0 to 1 if you havent already.
With those pistons and rotating assembly 400hp will be your max, I wouldnt go over that