Professional Products line of throttle bodies are generally considered by the performance industry as the highest quality throttle body available. These throttle bodies are precision engineered and many of them are made of aluminum die castings which is the same process used by the original equipment manufacturers.

Those that are not die cast are made from permanent mold castings, a superior casting process to the sand casting used by all other aftermarket throttle body manufacturers making cast throttle bodies. If you have a modified engine, a larger throttle body is required to reach the engine's full power.