max backspace?

You are right. I just remember something from a class on naval reduction gears were folded back over the shaft and attached as far out as possible to more then double the length of the shaft for strength. After looking at shaft yield formulas I see nothing about length only diameter so now I don't know why they do that in reduction gears.
I also tried then to see why they went to positive offset wheels and it seems like it may be to allow larger scrub radius to make steering easier and it moves the hub assemblies out further making more room in the engine bay for a transverse FWD setup. Why modern RWD cars and suvs are also using more and more positive is still a mystery to me but then again I wish every car made used the same bolt pattern, LOL! Even my GMC SUV (Envoy) with a 6 lug pattern is different then a same year GMC SUV 6-lug pattern (Tahoe), and they both are different than a current GMC (Arcadia) 6-lug pattern. What idiot came up with that? Now I can't add affordable common aftermarket wheels.