400 Vs. 440 into an A body

just do a 451... bare minimum performance, you're looking at 1 hp per cube. Thats using the worst chrysler heads and manifolds an eddy performer and 750 eddy carb with 11-1 comp and 509 purple cam. if you were to do a better build and went with alum heads, an 850 holley carb and some fat *ss headers you could easily reach 525+

http://www.arengineering.com/articles/451.html