Dr. Dyno said:
If you get the '93 head, I suggest you also get the '93 intake manifold and TB. You can port n' polish the head and bore the TB to gain a few more ponies. Keep your existing '89 fuel rail, sensors, wiring harness, and computer for simplicity, but you'll need to adapt your TPS to the HO TB. A set of Ford 24lb injectors and a MAP adjuster will take care of the fuelling.
If you're going to swap the stroker into your CJ rather than the XJ, the job becomes much more complex. You'll need to grab the fuel tank, fuel pump, fuel lines, fuel rail, intake manifold, TB, sensors, wiring harness, computer, exhaust manifold, distributor, and coil, as well as the engine from the '93 XJ donor vehicle.