i am young, and undexperienced, but i am willing to learn and i have ideas. ok so i have a 72 jimmy with a 400 sbc, the sm465/205 combo, with 3.73 gears, and 33x12" tires. i have a 203 sitting around, and i was thinking about making it a doubler, but i dont see me ever using it, as the truck already has alot of torque. I have crappy mpgs, and with these gas prices i have been looking at gear venders overdrive. i did some searching and came upon a site were they were talking about turning the t case around so the low was now .5:1 instead of the 2:1. i dont know if this is posible or a good idea, thats why i am posting here. i dont want to change the gears, caus then i would loose my low end for good, and the gear venders is to much money. i am just trying to use parts i have laying around, and still getting the results i am after. thanks guys, ya all have been so much help so far.