At 156k, you're squirrels are still plenty angry
@Michael Buenconsejo...and will be past 200k. Don't be horribly surprised if they go another 100k miles plus if the oil is changed semi-regularly. The 2.5 dies from neglect and abuse, not from use.
Doors, rollcage, seats, windshield, sidesteps, hardtop etc. will fit with only the normal headaches of swapping parts over, the internals of the transfer case, except the input shaft, will swap over. The Engine Control Module (ECM) doesn't swap over, but you can use it for a core if yours goes bad. A lot of the sensors do swap over, and it's nice to have a readily available supply of those. As far as I know, the wiring harnesses are universal as well. That's a huge bonus.
The axles are an easy swap, front and rear, but the gear ratios are going to make you hate life. I'd hang on to them though, in case you want to do a gear change later for larger tires. Some of the internal axle parts would be a direct swap.
I should mention the front disc brakes. The front discs and calipers have different dimensions between the '97 model year and the '01 model year. If you go to swapping them around, you would need to swap both the disc and the caliper to make it work. And do both sides! Jeep changed the depth of the rotor hat in '99 and while they fit just fine, they won't work at all unless you swap the rotor and caliper.
A whole spare parts TJ is never a bad thing, wish I had one.
