that guy was blowing smoke up your ass.. if you have a newer (83+) then it has the bigger oil seals and centering cones and things. people think they are limited slip, they arent. just pull the flanges off your old tranny and put them on your new tranny, or just use your old tranny, or just swap the inner CV joints on the axles you have in there. put 100mm flanges on your 90mm axles. thats what i did, its super easy doing the inner joint swap.