I'm also running a Carter mech, but without the regulator. If I were at sea level I might be in the same boat as you. But since I'm losing 100+ HP up here my need for fuel flow is also decreased.

Until you put it on a dyno or get an in-car gage you could be chasing your tail on this one. I do think it's fuel starvation though. The quicker the car accelerates the harder it is for a mech. pump to suck fuel to the front of the car.