There are a lot of options in automatic transmission control. JEGS has a great selection of transbrakes for drag racing applications. Transbrakes allow a full throttle start off the line and full fluid lockup when you push the button to release the transbrake. Full manual valve bodies are used for high performance applications where you don't need a transbrake to launch. Tractor pulling and monster trucks often use full manual valve bodies for better control over their automatic transmissions. JEGS carries forward and reverse shift manual valve bodies as well as manual/automatic combination valve bodies. Check out the new aluminum valve bodies that offer better heat dissipation over cast iron.