Brian, I been thru this one a few years back on a customers 84? chevy pickup, after repeated fuel pump failures he had me install a frame mounted electric fuel pump,easy deal right ? well it was till it came back on a tow truck because it had sucked a vacume on the tank. The original mechanical fuel pump had a return line to the tank wich creates a closed loop system thus avoiding the vent problem,(we plugged this line when we installed the electric pump)
You could install one of those style pumps if your using a mechanical pump and run a 1/4 return line back to your tank, or in the case of the customers truck I fashioned a tee off the 5/16 fuel line up by the carb & ran a 1/4 line back to the original return line, we did hafta play with this and wound up installing a # 65 hilborn injection pill in the return line too keep enough fuel preasure to the carb....that was 7 years ago and the trucks still runnin......