TH400 output shaft length
 

I know this has been covered lots and I'm sorry for bringing it up yet AGAIN buuuuuut.....

I need to change the tailshaft for my TH400 to the proper length for my NP208.

In my online searches, I found 2 different lengths with nothing more than "4WD output shaft" and "4WD 1980-1991"

One was a "rebuilt" (ummmm?) ebay special for 59.00US @ 6 7/8".

The other was through a company that specialized in transmissions and had one listed for 89.00US @ 6 1/2".


Which is the correct length?
Is there a output shaft swap how-to guide floating around the net for us wannabe DIY/ihaveawifeandthereforenomoney folk?