Another option is to use both. I am plumbing for an auxiliary electric 'inline' pump controlled by a switch on the dash:
The pic is an Airtex.
This is perfect for the scenario that 70Nova paints. The car has been sitting = the carburetor bowl(s) is/are dry . . . just flick the switch and prime the system. Start it up and drive away on the mechanical pump.
Best of both worlds.
That is exactly what I have done on several old Porsches (356), all hidden, for the same purpose, and retaining the original pump for original appearance and function. And just like you said, once it starts, turn the electric pump off and let it free flow fuel to the mechanical one.
