weber problem. floats too high?

[qsl]

427w. ford racing and a set of Jims webers.

I am just really getting this car drivable and i noticed while tuning that on the passenger side bank, if i screw down the mixture screw all the way the engine runs bad and wants to die out. However every screw on the drivers side does not really make a difference! I can turn the screw all the way down and the engine still runs about the same way. Whats really crazy is i can turn all the screws down on the drivers side and the car will still run about the same... Also when i rev the engine, i get a black puff out the drivers side exhaust and no smoke out the passenger side.

any ideas? Do you think the floats could be messed up on that side, leaking fuel into the carbs? what else could it be????