95 GMC Z-71

I am trying to figure out why my truck wont start.  I just finished putting new timing chain, water pump and multiple other items that don't have anything to do with the engine.  I got the timing set, fired it up and it started right off.  Took it for a test run and it drove great for about 5 miles then it just died.  I got it home and went through all electrical starting components, which checked out fine.  The motor will turn over, but now it wont start.  Does anyone have an idea what I could be missing or over looked?  Any help would be greatly appreciated.