Ok i have been searching the board and there is one thing i haven't seen answered anywhere. With my Chevy 8 1/2 10 bolt with a 2.56 in it if i wanted to go up to a 3 series gear i had to get a new differential. Is this the same for the Trak Lok in the Ford? Most of the posts i have seen people just talk about rebuilding the trak lok and putting on new gears. Can i go from a 2.73 to a 3.73.....or possibly 4.10 the more i read....without having to change the differential?