the longer the stroke, the more torque you can make with a given piston diameter. Since the 327, 350, and 383 all share the same piston diameter, the 383 will have the most torque, the 327 the least. (Granted you need cam profile, combustion chamber geometry, etc. as part of the mix).
Since the 327 is a good over-square motor, it makes a great 9000 RPM motor (the 302 is better). The 383 is a great torque monster maintaining the 4.0 bore.
its been a while since I have even looked up to see if a 327 would accept a longer stroke crank, however if it would, that is the direction I would go.
