Rest of the story... I returned the second Delphi pump and got an Airtex with a rocker arm that is identical to the original. Installed the Airtex pump and could still not get fuel to the carb. I tried both tanks with no luck. Enlisted an assistant had them crank the engine while I placed my thumb over the inlet hose on the pump to verify it was pulling a vacuum - it was. Performed a fuel line test by blowing through the line back to the tanks and discovered that regardless of the fuel tank switch position the air only went to the right side tank. Question, does the fuel tank selector valve only operate when the engine is running? All this time I new that the right tank was very low on fuel but did not think it was empty - well it was. We put abut 2 gallons in the right tank and, behold, the pump pumped and the engine started!! Now, of course, I wonder if the Delphi pumps were working the whole time. A point that I would like to make is to validate comments made by other folks on the fuel pump replacement process regarding the retention of the pushrod during installation. That is, the best way to do it to use a longer bolt in the access bolt hole. That way you can be absolutely sure the rod stays in place during the entire process.