I am sure somebody will chime in with locations as well as more specific info about the two types of dynos most commonly used. The Dyno jet is known to yeild higher rwhp #s than the Mustang Dyno. The reason being, is that the Mustang dyno will run your car with a pre-set load on your engine. To make it as close to real life driving. I however, have always used a dyno jet and have always produced numbers that were confirmed by performance at the track. You can't really go wrong with either. Best of luck and let us know how she runs!