The 4.25 stroke is the way I would go. The torque should come in maybe 100 rpm lower, which isn't much, but hey, if you don't spend anymore $$,,,,,,,,
The actual cube difference is 2.6 percent, worth while to me. You just can't beat cubic inches in a street motor, even with restrictive heads. At 512 to 540 the torque gets brutal and gearing can be reduced to match. I would consider about a 3.55 gear with a big motor because street traction just isn't that good anyway.
The 2.2 rods and bearing journals take a bunch of stress out of the bottom end due to a fair amount less weight. The pistons are a touch lighter as well.
Weight comes off the crank shaft as well when the crank is balanced. Out dated sfi eight bolt flex plates can be had cheap, if you can find an expired one from a guy like me that puts few runs on his stuff and needs to replace for SFI cert anyway. Don't be afraid to look into a 4.5 crank either. The rpms come down and the stress on the parts is even less because the rotating assembly in a 440 block can use a 7.10 chev rod and a much shorter piston. I have run 4.5 stroke with iron heads and peak power was 5200 rpm or their abouts with a tunnelram and 590 cam.