Bigpopa

Before I get flamed LOL I did use the search button and did not find my answer so here we go. My XJ started life with a np242 with a 35 I did a swap to an 8.25 well my DS was a hair to long. I picked a shaft up from Beezle on the board for an 8.25 installed new U-joints and my slip yoke on to it and compared it to mine and it was about 4" shorter than my original. Well I got installed and it has just over an 1" of spline engagement which worried me well I got into it and drove it and it is smooth no vibes. My ? being is a np231 case longer than my np242 meaning distance from tranny side to yoke side?

caged

the 242 is a bit bigger of a case than the 231, but the 8.25 has a longer pinion than the d35, so the drive shaft will be a bit shorter, if it was going into the same equipped jeep.
you will also have to take into account whether the donor shaft was from an auto or stick.
all these make up slight differences, so there's a few different drive shaft lengths.
if you were to find a slip yoke off a yj, it is a bit longer and has better cuts for better angles. just pop that u-joint and swap the yokes.

Bigpopa

I forgot to include or think about that I am not sure what the shaft that I got came out of but I have a AW4. So I am wondering if that shaft that I got is out of a stick XJ cause of how short it is........