I have a fuel leak coming out of a nut facing timing cover , I had its checked and they said its cracked , is this common on 1st gen 5.9 ? any ideas where to get a pump and how much$$$$$

 

I had similar experience with '90 W250. Recommend you go to a injector pump shop with their own VE pump test bench - meaning you get a knowledgeable diagnosis and experienced repair/replacement options instead of just "I don't know, we'll just replace it" It might be cheap, but it could be expensive to fix any underlying problems. (about $1200-$1500 for a full replacement and filter(SLC,UT). You will love how it runs after it is fixed.