As far as the magnum, skip them. It's all smoke and mirrors.
Running the engine rich won't add 17% to hp or torque, but it will cause the heads and intake manifold to build up carbon deposits and eventually cause the engine to knock and ping. Running rich is usually done on turbo cars under boost because the extra fuel cools the combustion chamber, but on a naturally aspirated engine, it's bad news.
I also think the dealer can remove the speed governor. You shouldn't have to pay that much for a kit to remove the speed governor when you can change the setting in the PCM.