Electric pump before or after mechanical

Is there any possibility you could just have a bad mechanical fuel pump and need a new mechanical fuel pump? Did you cover that I can't remember?
I have checked the pump repeatedly. It is an Edelbrock 1720 and the check valves will hold for days.
Electric pump INSTEAD of mechanical, if you just GOT TO run an electric. .
I don't HAVE to go electric. I am just thinking the electric will 'prime' the carb when I do want to start it after 3+ days. By using the lp/lv pump, it won't over pressure the needle valve but will 'charge' the fuel line prior to starting.
Sean