[frnkeore]

It wouldn't be to hard to test a square vs a under square combo. You could even test a over square but, the cranks would expensive.

The combo's would be:
3.202 x 3.750 = 241.58
3.375 x 3.375 = 241.55
3.440 x 3.250 = 241.65

Or
3.19 x 4.00 = 255.75
3.44 x 3.438 = 255.63

I don't think there would be any difference in HP for the last two but, there might be some slight difference over the 3.75 stroke, in reduction of friction.

The friction reduction is why Ford came out with the short stroke OHV engines, in '52 & '54 and they advertised it, in their adds. They continued on with it in '60 & '62 with the Falcon 6 and Fairlaine V8.

The Mobil Economy Run was important in those days and I think that might have, had something to do with it.