When I went from a BA10, with an internal slave cyl., to an AX15, with an external slave cyl., I first kept the same clutch disk (CD) and pressure plate (PP). It shifted fine, but not smooth. I research on RockAuto the parts numbers. The CD part number stayed the same throughout the XJ/MJ production. The PP part number changed when the AX15 switched from internal to external slaves. That was 93 model year.
I would suggest getting a PP based on if you have an internal or external slave. For me, both worked; the later year's part worked better.
Of course, you will need the correct throughout bearing.