The Ford 9" has about 1.8" of pinion offset (I forget the exact number) from the pumpkin centerline, so if you want the driveshaft to be 100% perfectly centered with the transfercase output (laterally) the rear axle must be built with a slight offset.

Do you guys sweat this type of detail on your builds, or does it not matter that much??? My concern is mostly about extra vibration and/or wear on the driveshaft u-joints during extended highway usage. For guys who are trailer-only type rigs, this is probably a non-issue either way.


-G
:usa:

I have built them both ways.
'usually' the customer wants the "center" as the pinion itself irregardless of the offset.(rear)
Other things to consider is where you will end up with axle length(s) and if you can use existing shafts with a 75$ respline vs having a custom one made at 400$ plus.

I am running a Stak 3 speed Tcase and its' output if offset a lot , so I offset the rear to match.

So, yes, it is worth considering, the tube cuts easy enough, you might as well strive for optimum angles. All 4 of my shafts are different lengths, just like a stock 'mog !

On my rear I centered the pumpkin and have the pinion offest. It's so minimal that you don't even feel it through the driveline.

How critical the misalignment would be, to possible vibrations would depend on the length of your front driveshaft, but I think generally, assuming t/case output and diff input flanges are parrallel, a driveshaft doesn't know nor care if the misalignment is lateral or vertical.
On the subject of axle shafts. does anyone over there have a brooch for doing Mog internal splines?The reason for asking is that when I needed a longer than stock shaft when making up my LandRover portals I used a stock short shaft with a brooched female splined sleeve plus an extension stub shaft to make up the length. That way I only need to carry one spare rear shaft set plus one front outer shaft.The length of spline in th sleeve was sufficient for the stub shaft to be telescoped out or inwards to match the required length of the 3 locations.The front r/h/s not requiring an extension.
Agrover.