Your best answer will come from calling the service department at your local GM dealer, or by reading the truck's owner's manual. There were lots of conflicting reports when I asked this about my '98 Ranger's 5 speed manual tranny. Turns out, the answer was different whether the truck was 4wd or 2wd, also manual versus auto trans. Your owner's manual should spell it all out very clearly. If you don't have the owner's manual, the dealer should be able to tell you.