OK, thus far other than a few appearance modifications, my performance modifications have been pretty much non-existent. I've only added Flowmaster axle backs (which is basically for sound only) and a BBK CIA. After some debating, I've decided that my next modification will be purchasing an SCT Tuner (either the xCal 2 or the xCal 3) and a set of FMS 4.10 gears. Not knowing a lot.....make that knowing NOTHING about computer tuning a car, I'm not sure how it all works. My plan is to order the SCT tuner the next week or so, then add the gears some time in early April. So my question is, can I add then tune to my car now and then change the gear ratio in the computer with the stock out of the box tuner? Will I need a custom tune for the gear? What all factors do I need to consider? Any help from anyone would be most helpful.