Mechanical fuel pump - multiple bad pumps ??

[MYOUNG]

Be advised... Long fuel pump saga to follow.

I recently bought a 1969 GMC 2500 camper special. It still has the original 350 motor in it. I decided to rebuild the carb because it looked like a filthy mess and while I was at it I also decided to replace the fuel pump and line from the pump to the carb because they were fairly cheap insurance. I went to the local Autozone and picked up a Delphi brand pump and installed it after finishing the carb rebuild. I started the engine and it ran for about 1 minute before suddenly dying. After poking around I realized that the fuel pump was not pumping anymore so I removed it and discovered that the lever arm had failed internally and the tip of the arm snapped off shortly after starting the engine. I returned the pump and got another as a warranty replacement. I installed the second pump and started the engine again. The engine sounded fine and fuel was pumping inside if the inline filter. After about 45 seconds I heard a pop sound from the pump and then the fuel in the filter stopped moving around. 30 seconds later the engine ran out of fuel and died. I removed the second new pump and it had failed the exact same way as the first. The lever arm had the tip snapped off on the inside of the pump. I returned the pump again and then bought a third one from another parts store. The third pump was a Spectra brand it it looked way better. The casting on the pump body was thicker, the mounting boss was thicker, and the lever arm was also thicker steel. The third pump seamed to work as I put about 30 miles on the truck without issue. I was recently setting my ignition timing and adjusting the mixture screws on the carb when I noticed some wetness on the top of the fuel pump. I touched it with my finger and smelled. It was gas. I thought that gas may have been leaking down from the filter and following the fuel line but it was dry. Seconds later fuel began spraying out of the weep hole on the side of the pump and I ran around to shunt the engine off before a fire started. I am beyond frustrated at this point and am about to just put an electric pump on. The old pump that I removed originally looks the same as the rest of the pumps I have installed so I dont know whats going on.

Could vapor lock from extended periods of high idle damage a mechanical pump??

I was running the truck for about 30 minutes while I was moving the timing and mixture screws around. I dont think my fuel line from the tank is plugged as it dumped plenty of gas on me when it was replacing the fuel pump. The inside of the tank looks really good.

Has anyone else had similar issues with quality on these cheap parts house pumps??