rd, I just finished replacing the timing case gasket on my 98 12v. The step by step link illflem gave you is not truly step by step, it is an overview. One key thing I learned when I replaced my gaskets is that the fuel pump must be pulled before the camshaft can be removed. I spent a total of 12 hours doing the job. I could have had it done a few hours sooner but spent a lot of time looking for a lost socket I feared had been left on a bolt inside the timing case ( it wasn't there, yes I did take the cover back off to see !) and also used up a bit of time retrieving the fuel pump plunger from the bottom of the oil pan. ( no wonder I couldn't get the truck to start):--) I don't know how much the new timing case is but I spent about $125 on gaskets and seals. The job was identical but I was able to use my old case because it was not broken. By the way the local diesel repair facility quoted me $2,200 to do the job... ..... good luck!Oo.