Interchangability...is that a word??
Anyway - I own an 88 Sami and have an opportunity to get a 93 Sidekick for next to nothing. It has some "motor issues" that the current owner is unsure of.
What parts are useful for both? If the engine problems are minor, the engine in the kick would be an upgrade, right? Anything else...tranny, rear end...??
The engine upgrade would require a simple-to-install transmisssion and engine mount adapter kit. A 1.6 engine would also give you the benefits of fuel injection -- helpful for preventing fuel starvation carbureted engines are prone to when operated at extreme angle as found when offroading. Grafting the Sidekick harness is a bit difficult but not impossible. You can even purchase a modified harness. fuel injection also gets you better mileage.
Locking hubs are interchangeable.
Rear dif is only interchangable by grafting the complete pumpkin onto a Samurai rear axle.
Front dif can be installed with the aluminum third member housing but is stronger when installed in a steel third member with an adapter kit.
Transmission and t-case are not an easy interchange as the t-case bolts directly to the transmission. The Samurai has a divorced t-case.
Not much else is easily swappable.
for general FAQ information, try
http://ackerdackerly.com/faqphpBB/index.php.