I would build it like a 383. Use the closed chamber heads and get a cam in the 230 to 240ish @ 0.050 range a good intake and carb, headers, and it shoudl be an easy 430/460 hp/tq motor. Compression is the issue and open chamber heads are harder to work with in this regard.

Assuming it's a cast crank you can go up to 500 hp easily. If you had a forged 383 crank laying around I would use it for insurance, but the cast is fine for mild builds...just creates some unique balance issues during the build. No big deal really becasue it is good insurance to nuetral balance the rolling assembly anyways.