RAMM - My generalization was just that - simplifying to clarify the idea to more people. I am not debating whether a 4" arm will produce more torque at a lower rpm or more at peak. With respect to your builds - what parts would be different in order to complete the respective packages and attain the levels we're talking about? the OP posed the restriction of reusing everything but the crank, rods, and pistons. To me that means much of the possibility of the larger stroke goes untapped and therein lies my disagreement with the builder. In my opinion it will take adjustment of parts choices, otherwise known as spending more money, to realize that potential. In this I think you and I agree. In my experience, and based on the majority of my customers the single biggest issue is money. It's the most important part of the puzzle.
I have no dog in this fight. I don't own the car, nor am I pocketing any cash for building it.
-Naysayer©