motor swap!!!

i have a 1990 jeep wrangler 4.2 carburated 5spd ax15 trans np235 tranfer case and i need to know if i can drop a 91 4.0 fuel injected out of a cherroke in to my jeep legaly can anyone help me!

You probably can, but you will need ALL the harnesses, computer and while your at it get the tranny too. Not sure, but the 5spd should bolt up, one thing though, is the XJ motor off and automatic tranny? If so you will need to open up the oil pan and replace the mian thrust bearing with the one for a manuel tranny. With the clutch and pressure plate, more pressure on the crankshaft. Also, you will need to get the fuel tank too. There is a long list of items you will need.
Why do you want to convert to the 4.0 f.injected. I have a friend with the 4.2 in her CJ-7, with 115K it still running great.

why would you need to replace the thrust bearing?you would have to put a pilot bearing in the crank but there is no special thrust bearing