Carb choice

Probably for the better rod ratio and its resultant reduced internal friction due to less piston sideloading against the cylinders, and the increased piston dwell time at TDC and BDC with its attendant advantages in completeness of combustion and control of preignition.

Long-rod 225 builds are well known to work well even in near-stock configuration. You don't seem familiar with them. That doesn't mean the idea's nutty, it means…you're not familiar with them.
I may not be familiar with that particular combination, but it would be impossible for me to be more familiar with the cause and effect of geometrical changes to the bottom end of a high performance engine. Long rods move the torque curve higher. Period.