the gears and the t-lok is not what's going to kill you (espcially if you get a used set that's good) it's the installation $$ wise.
Midwest Mustangs, Inc. - Main
Give Terry a call, he also sells on ebay. Located in TX. Gave me a great deal on some 3.73's for the 7.5 and a t-lok used off a ford Ranger, only $110 shipped.