My converter is a 9 3/4" built by a local company. In 2011 I pulled it to have it modified for a bit less stall. It was originally rated at 3000 but at freeway speeds it just felt lazy, like a feeling of freewheeling. I hated that.
It feels much better now. Its not as if the converter is so tight that the car is a slug out of the hole. It will boil the tires easily. Maybe with better traction the converter may be a problem.