there arent any o-rings on the poppets. i wouldnt worry about the distributor too much right now. focus on the fuel issue. you need to remove the fuel filter and put your tester inline with the fuel line, but plug the engine side of the test adapter to ensure anything upstream of your tester isnt getting fuel. then pressurize the system and check for leakdown. if you lose pressure, you know its the pump. if you dont, its somewhere upstream of the filter. then youll have an idea of where to look. not saying leeann is wrong here, but when i was instaling my distributor, the FSM showed a picture of how far off the distributor could be from the timing arrow on the distributor base. looked like about 1/4 or so. though that was just more about accuracy than play. if you have a cowl induction hood, remember that the distributor is right under the cowl, and it your trucks age, the hood seal might not be in the best shape. i think you should replace the cap and rotor, or at least clean them up, and see if you get any improvement AFTER you handle the fuel problem. and for the egr, make sure when you clean it that you physically move the pintle valve up and down while spraying with cleaner to clean the shaft and ensure proper movement.