Turbo 440 duster
With that turbo and say only 20 lbs with the right cam and heads, 1000 hp should be somewhat easy. Imports with 3.0L motors need 40+ psi and alcohol to make that much. David Freiburger (The F-Bomb Camaro) made that much with 14 psi on a 400 Chev. A 440 should be easy; but what do I know?