I will venture a guess that your cam does not have the eccentric lobe to drive the fuel pump pushrod, or, the pushrod is not on the lobe if you installed it yourself.
However, you need a fuel pressure regulator with that elec pump.
69 RS Conv therapy program, Autogear M22, 8-pt cage, with a new 410! SOLD
New therapy program - 68 Coupe. Will be survivor exterior, modern underpinnings! SOLD
67 Belair with perfect floors, pinchwelds and firewall. Hmmm!