I have a 68 firebird 350 2 bbl 4 speed
Previous owner added a 4 barrel and had issues with it ever since
I purchased the car as a project car so started with a non runner

I added a edelbrock performer intake and went thru the 72 q-jet
My problem was previous owner cobbled a 68 2 barrel throttle cable and that didnt have enough length to properly open the throttle. Replaced the cable with a proper 4 barrel cable and it ran like a beast! At least for a little while

The car started cutting out at higher RPM's...Car would pull strong thru 1st and 2nd, but shift into third...while accellerating, it would fall on its face

Another pontiac buddy told me its a fuel delivery problem, and suggested replacing the fuel pump. I took off the old pump, and replaced it with a new autozone...
Nothing...Car is not getting fuel to the carb now.
I turned the motor over by the crank to line up the eccentric and there was a little resistance but the pump bolted up, connected the fuel lines...and no fuel

I pulled the new pump off and put my old pump on
Again...No fuel to the carb
Is there a trick with the eccentric to the fuel pump rod?
What am I missing?

Thanks in advance!