Driveshaft question. Stock Z71 bigger then non z71 ?

[PitchBlackC3]

I don't think it has anything to do with Z71 vs non-Z71, I have seen both styles on both types of truck.

As far as the diameter, an aluminum shaft has to be wider diameter to have the same strength as an equivalent steel shaft.

I don't know why the alloy shaft would be shorter, that doesn't really make sense, but there couldn't be much difference even if they are.

Honestly for off-roading, I would rather have the smaller diameter, less easily dented steel shaft.