np242 spline count

Hey guys i did a search i think my np242 has a 21 spline it's a 87 cherokee. i just want to check to make sure with you guys. i want to put my dana 300 behind my aw4 tranny to run a pass. side front end. i was hoping it was the 23 spline one. you guys have any idea's. thanks

It's a 21 spline up to 89' at least, 90' was said to be the 23 spline implement, but 91'+ with the 4.0L HO for sure.

thank you