I'm trying to source a 2.7L for my Gen 1 Tracker. I think it's the answer to my power needs (will be towing with it). I have Toy axles (opens up diff gear options) and a Samurai T-Case (opens me up to using a doubler, and it's 1.4:1 hi-range reduction).

I'm having a hard time finding the stock diff gear ratios, trans ratios etc. I'd prefer to do an automatic, but I've heard there 4-speed and I've heard they're 5-speed - which is it (or both?). Basically I'm trying to find the easiest way to have the engine at stock RPM in hi-range (for towing up the mountain), and (if possible) lower the low range for when I'm in the rocks. Anyone know if the Kicker III (that's the Samurai t-case one right?) will work, or the adapter from Rock 4x?

XL-7 was available with a 4spd auto until the end of 03 then went to 5 spd auto in 04 thus  your varying reports
 ratios were 4spd
http://www.cars.com/go/crp/specifications.jsp?acode=USB30SZS082A0&groupDesc=Optional+Transmissions&equipDesc=Transmission&equipData=4-speed+automatic+w/OD&availableOptions=4AT-01&aff=detnews
and for 5spd
http://www.cars.com/go/crp/specifications.jsp?acode=USB40SZS082A0&groupDesc=Optional+Transmissions&equipDesc=Transmission&equipData=5-speed+automatic+w/OD&availableOptions=5AT-01&aff=detnews
the 4spd auto had 5.125 rear gears where as the 5 spd auto had 4.30 (same as 5spd manual)
I don't know for sure if the kicker will hook to the newer t case (doubt it)
but if you can get the 5 spd auto you should have plenty of gear with 5.71's and a vehicle that weighs 1000 lbs less
or just make your own kicker style setup
http://bbs.zuwharrie.com/content/topic,23639.0.html
and run what ever ratio you want in the toy axles and make up the difference in the sammy case
a little more info for you wrap your head around
http://www.grimmjeeper.com/gears.html
you will have to choose "enter your own numbers" but you can pick your rpm's mph tires ratios
and compare that to stock side by side
once you get the hang of it you'll love it

This makes me think how hard would swapping out an 02 AT 4sp for an 04+ 5sp be?  Should bolt right up.  Would one just need to swap out the ECU also? hummmmmmm

We will be bolting up our kicker 2 eventually.

The auto trans works with the older tracker t-cases.

Our XL has 33's with LOTS of power, its awesome.