I dont believe it will fit. The whole front is different between the XJ/MJ and the YJ. The YJ is based on the CJ dash. Its just a flat panel with all gauges and instruments bolted to it. The MJ is a separate components that tilts down.
That said...with the proper tools, enough time and $$$, anything is possible.
87 Comanche, 4.0, AX15 (formerly BA10/5), D44
84 CJ7, 4.2, AX15 (Formerly T5)