So im getting ready to put the new rear end in my 98 bravada, and i wanna change the diff fluid front & rear, im looking into royal purple and i am wondering what weight to use, anyone out there running rp let me know what your using and if you like it, or any other brands for that matter. Also what rp would be good to use, already changed the oil & trans fluid just had a new trans installed so i figure i might as well change all the fluids, god knows when they were or if ever changed its just hit 138k so for peace of mind i wanna get it out of the way plus winter is comin always gotta get ready for that.