'56, Not all hope is lost, don't you worry!

A quick and dirty way to magically fix a carburetor is to run the engine at high idle while standing close to the carb. Cup your hand over the throat of the carb until it nearly snuffs out, then repeat a couple of times. This will create a huge amount of vacuum within the carb and can help to blow out any restrictions that may have been missed on your rebuilt carb. The carb you are running may be a timing issue more than a fuel issue from what I'm hearing. Bmorgil is the master tuner, so he will have some good ideas to try. Carb tuning is a science and an art all wrapped up in one.