B&M Converter is bad

Converters don't just turn on at 2000 R's or whatever they are advertized at.
I would think that it tries to take off because the idle is so high, and the idle is so high to compensate for mistuning somewhere.
This is indicated by the huge RPM drop when you put it in gear.
I think this is where everyone is headed with this.

You did say you wanted to be sure.