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"Biggest debate I'm having at the moment is if I should stay with the 4.440 x 4.150, or increase the stroke. I could slide a 4.50 crank in there to pick up the size as well as the compression. I'm just not sure that bigger is better when the motor is already limited by the heads. Maybe smaller with more RPM makes more power? "
That was exactly my question when I built the motor I now have. I felt that the 4.15 stroke x 4.5 bore combo offered the best size for the 440-1 heads. Maybe I was off the mark, maybe not. I had a billet 4.5 crank at the time, chose the 4.15.
It would seem that at some point the total amount of air filling the cylinder at a given rpm must be reduced as the motor gets bigger, reducing running compression? Ring friction goes up, the biggest drag on the motor. Crankcase windage gets worse. Which would start to clip the hp up top more than just the differance in size of the motor.
At this point I still wonder if even smaller motor with the biggest bore possible might be the answer, say (edit)4.500 by 3.9 in strke for about 496 cubes. That would put the motor more in the sweet spot of what I have, a running range of 6400 to 7500 rpm..

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