taylour,
The term 'loading up' refers to excess fuel...the carburetor is dumping too much fuel into those cylinders, and when it manages to burn, it burns very rich and leaves behind the sooty residue on the plugs.
The important float setting is called 'float height'. This is the distance from the bottom of the float itself to the base of the carburetor casting. Sometimes it requires the gasket to be in the equation. This procedure is done with the carburetor removed and split into pieces. It's hard to describe so I have linked a picture of it being done on a carburetor.
The linked picture shows a gauge being used, and the gasket in place...It's a hard procedure to cover for a first time carb adventure.
Your rig has unconventional carburetors on it as I recall. A float that is waterlogged, or partially sunk will cause your type of problem.
Do you have any friends that could help you troubleshoot and repair this problem?
http://chevy.tocmp.com/Rochester/9D7p13.htm Stuart
