Thanks George,

I remember reading another post on this board saying the auto and M41-specific shafts could be interchanged on the 140 model.

There was also a Volvo mechanic, selling a M41 front driveshaft on eBay, saying that the auto and M41 shafts cannot be interchanged on any model, from the 444 all the way up to 145,etc...

I guess I'll just have to muster some more patience, swallow some more dirt and get crawling again for eventually accurate measurements.

I'd like to keep my car's downtime from trial-and-error to a minimum while I do the swap (but I have a feeling I won't escape it).