I am in the middle of installing a sidekick automatic into my sami. I had the T-case modified into a Kicker3 (OTT) so its not exactly what you want to do. You can get it in there without a body lift or cutting, if you dont mind an ugly transmission tunnel. I personally wouldnt go with the tracker case, it uses slip yokes (but could be converted to flanges), and you will have a steep rear driveline that might come close to to the floor and crossmembers. Also, the only (high range) reduction would be in the axle gearing. 5.12 gears will only correct for 30-31" tires. Also, the low range gearsets are kinda pricy. I think an automatic will be sweet in a sami though, the 3-speed is a pretty good transmission for its size and is somewhat easy and cheap to overhaul (as far as automatics go) yourself.