You might not need a sleeve for the front of the crankshaft. The front seal kit(for my '97, the Cummins P/N is 3804899) comes with a seal installer to press in the seal. I checked the location of the stock seal in the front cover before I removed it. On my truck, when I used the seal installer supplied with the kit, the seal ended up being farther in the cover, so now it's riding on the crankshaft in a different location. . Maybe they did this on purpose to provide a virgin surface for the new seal to ride on. I agree with everyone else. While you're going through the work to change the front seal, tab the dowel pin and check the other bolts inside the front cover.