Manual shifting: Necessary on vehicles with vacuum operated transmissions or when you desire to be able to select your own gears, as in racing applications. These come in two shift patterns , forward and reverse pattern each of which can come with or without engine braking.
- Forward pattern: Common in boats and off road vehicles the up shift postition is toward neutral, P-R-N-3-2-1.
- Reverse pattern: Common in drag cars and street cars, typically for those who worry about over shifting into neutral. Shift pattern is reveresed for all the forward gears, P-R-N-1-2-3.
- Engine breaking: These valve bodies are most common for vehicles which are in and out of the throttle and/or do not want the engine to freewheel in gear. Meaning when you let off the throttle the transmission will hold and the engine will slow down the vehicle, similar to a stick shift when the clutch pedal is not depressed. These are most common for off road trucks, rock crawling and street cars.
