1953 Flathead acceleration issue

[53_mercLuke]

I just rebuilt my holley teapot carburetor and it runs great at idle but when I give it 1/4 to 1/2 throttle it spits then dies. The float looks level from the top. I replaced the fuel filter and the pump is mechanical but not that old. I also replaced the distributor cap and rotor and the vacuum advance on it to eliminate that from being a possible issue. Any other thoughts?

Thanks