No, they should be very different
yes, swap your grille with a tj/cj grill with the hood.
No I have a 95 Jeep Wrangler and a 78 ford F150 and the rims will not swap.
There is no other direct swap.
or what will make the 1990 jeep wrangler 4.2 and 4.0 engine swap out
To do this swap you will need to swap out the engine, transmission and transfer case as a unit. And there is a host of other things to change including the motor mounts, wiring, etc. This is not an easy swap by any means. You would be wise to sell the 2.5 Wrangler and get one with a 4.0.
You will need a different trans, engine, radiator, wiring harness, computer, etc..
You need to provide more info on the size and manufacturer of the v8 you wish to swap, also trans selection, 4wd or not?
The hard top is interchangable for those model years. Simply swap the hardware and then install the hard top.
NO. there was a body style change in 1997. Not without some fabrication. I have done a door swap between a YJ donor and TJ. the doors are physically the same size but use different latch mechanisms and the location is different. Its fairly involved and not worth the effort in my opinion. I did it back when TJ doors could not be found at a reasonable price in 1998.
complete engine, wiring harness, and computers. you may also need the tranny if they are different because the computer needs to connect to the tranny as well and won't work properly if they're different.
yes. you may end up with a wire or two that goes to nowhere but the basics are there and the vacuum lines are the same. i have a 91 with a 92 motor and there are at least 2 wires to nowhere but it doesn't affect the jeep at all. your check engine light may stay on but it is probably because of the wires that aren't connected. no big deal.
yes, the axles are a direct swap