[Big-Foot]

Mike - I'm sorry to hear of your trouble.

I presume that the floats are not sticking and that when you double-check the levels, they are where you set them (no fuel spilling from the sight-holes).

What fuel pressure are you running? If higher than 6psi, turn it down. I set most cars - even our race cars to 4.5 to 5 PSI. After setting the pressure check the float levels again as they will change with the different pressure.

Ignition system - where is your advance at? Do you have a good strong spark? If you have it (and I recommend it) do you have a vacuum advance distributor? Is it connected to ported or manifold vacuum?

Synchronizing carbs is an art and not typically done correctly the first time by a newbie. If you have a good "ear", you can set the carbs by the sound of the "suck" by using a piece of windshield washer tubing, down the primary throat of one carb (listen) and then down the throat of the other carb (listen again) - adjust so both carbs have the identicle "hiss"...

Remember one thing - you only have 427 cubes you are working with here. That engine would be just as happy as a clam at anything under 50% of it's power band on just one of those 600 Holleys. Right now you are feeding it a lot more fuel than it would normally get if you have the idle speed screws out of synch and the fuel transfer slots are TOO exposed.