Somebody will correct me if I'm wrong, but I believe a '94 10 bolt would be for a 22 spline axle. You'd need a 26 spline diff for the newer tracker/vitara which came on '96 and later models. You can count the splines inside the spider gears (where the axles slide in) on your 10 bolt diff to be sure. I think the spline count thing applies both front and rear.
Also, I don't know that a 10 bolt diff would slide over the 12 studs on your axle casings anyway - unless you're swaping the cases as well.