I've built a lot of 302s because after my '71, I became a Fox 5.0 fanatic. A blueprinted stock rotating assembly from a late-model 5.0 (1993 vintage), forged pistons, plasma moly rings, 9.75:1 compression, shotpeened, polished and upgraded ARP hardware for the rods, Edelbrock Performer 5.0 heads (170cc intake runner), 1.7 ratio roller rockers, street legal roller cam, shorty headers, GT40 intake - made 400 hp at the crank.
I would say with the RHS heads and the bigger cam you may have some more top end, but I would guesstimate 400-420 hp at the crank. What are your times at the track?