I'm gonna confirm the theory of the 89-95 trackicks are indeed 22 spline, 8 and 16 valve. The 96-98 fronts are all 26 spline. I've torn enough of these apart for use in sammys to know this.
Yeah.  I have no idea where I came up with the 23 spline number instead of 22 for the 95 and earlier.  I just verified it on ARB's website (easy to find there).
Rears are all 26 spline (10 bolt or 12 bolt).
The 22 spline fronts are 0.94 inch shafts, and the 26 spline fronts and rears are all 1.08 inch shafts.
EDIT: I got confused on the spline count of the smaller shafts, because I don't have any of them any more on my trail rig (of course, my daily driver still has stock 22 spline, 0.94" shafts).