Thanks to everyone for all of the good suggestions. It still doesn't make sense to me why the same carbs would work well on a 383, and behave differently(lean bog) on the 440. The one thing I forgot to mention is with these carbs on the 383 they would open slower. When installed on the 440 they seem to open instantanously. In other words at cruising speeds, if you open the throttle quickly to say 1/3 to 1/2 way they open imediately, where on the 383 it would take approx. 1.5 to 2 sec. after hitting the throttle for them to open, and they would transition more slowly.
No 2 engines are the same. Did both engines have the same cam, head flow numbers, Ignition, etc…? I would install an Air/fuel gauge and take it from there.
