The Ford 5.0l engine is a great engine for a Jeep. That being said...
Well there is a lot of work involved. You have to find out what your states smog laws require. Then you have to find a engine that works with the laws. You need to find a trans that works with the engine, a t-case that works with the trans. You have to build mounts for then all. then you have to install them. The stock jeep axles will not survive the added power. So now you have to find axles that fit the vehicle and work with the t-case. Then you can swap them in. At that point you are ready to start to run it and work all the bugs out.
For an experienced mechanic and welder/fabricator this can take from a month to eight months once everything is rebuilt. It is very commonly a $8,000 project. A rebuilt 4.0l has pretty good power and can more easily be modified to create more hp/tq. This means less money and no fabrication. As well depending on the axles already in the Jeep you can just get chromolly shafts and gears and be good to go. If it has a BA/O transmission get a AX15. With those modifications you have a good vehicle with a lot less cash and skill needed. You can do most of the work with the help of the Haynes or Chiltons manual in your drive way and its all bolt ins. The only exception is the ring and pinion swap that you will need to match to your tire size. I'm not trying to make it sound worse than it is. You do some research and a lot of reading and decide for yourself. Good luck and have fun.
" If you ain't been stuck you ain't wheeling enough." - Me
When all else fails... ham radio is there!