You will need a different nose cone on the front of the AX15, they are different between internal and external slaves.
A different throw out bearing and the fork that it rides on.
A different clutch master cylinder, and the line. The stroke on the master has to match the slave and they are different.
And the external slave bell housing.
'87 YJ, 4.2L built and bored, 8" of lift, 8.8 rear, AX15/NP 231J, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...