[dimefury]

sounds like a vaccum leak before the carb.

check the intake manifold gasket and carb-to-intake gasket for leaks.
also look for any unconnected vaccum lines.

to test an intake manifold gasket all you have to do is take some non-chlorinated (important) carb cleaner or brakecleen and spray around the gasket with the engine running. if the idle gets faster, you have found your leak. the idle increased because the engine sucked in the cleaner and used it as fuel.