So I am putting 32's on my '88 Sammy soon, and will need lower gears. I have heard that it's possible to put track/kick diff gears in Samurai front/rear ends with special adapter shims(I think Rocky Road has them). Anyway, there is an '89 Sidekick Sport(auto) in my local U-Pull-It yard and I was wondering if those gears(4.62's I think...) would work. There is also a Tracker with a 5-speed of roughly the same year(not sure what gear ratio). Any info on this swap would be greatly apreciated.

You need two front Track/Kick diffs. Autos and manuals are different ratios.

I did this, with very nice results!

To add to rhinoman's comments, try marking and spinning the axles counting the output revolutions in relationship to the input revolutions on any salvage front axle that you run across.  Find two that match (mine were 4.62s out of two 3-speed automatics) and buy them.

Strip the ring and pinions out of the difs and use them.  Do not use the aluminum housings.

The rear axle is physically different from the Samurai and the differential cannot be easily transplanted.

Me and a friend just put a tracker rearend and a front diff in my sammy and it works great!
You will be wider in the rear and need 2 in. spacers in the front .I'm very pleased with mine.