383 or 440?
You can make the same HP with ethier, 383 going be higher in the RPM ranger than the 440. The 440 gonna make more torque and need less rear end gear than the 383. I'd would put on the 383 heads on the 440 with a cam, intake and headers just don't go to big on the cam with the lower compression even though the closed chamber heads will bump it up a bit.