pre '91 242s have 21 spline (I have one going into my '87 Comanche with an AW4 in place of a BA 10/5 as soon as I get someplace and time to work on it!) The input depth may be different. When you get the tcase, measure how much of the trans shaft sticks out past the edge of the trans adapter. (flat edge and depth gauge usually works) If theya re the same, then no prob. If not, then you may need a 7/8" spacer or it may be too shallow. Not a big deal on a 4 cyl, but other setups are tougher. Found this out when we went to put a NP219J behind an AW4. Both were 23 spline so we figured, no probs. Needed a spacer to make it work! (I have the spacer now, but that rig is getting a diesel swap instead)