Ford E4OD and 4R100 89-up Perfect for Street Sport Trucks, Adds Durability and Performance. Includes calibration plate for firmness adjustments. Has gear command feature for early pre 1996 Valve bodies. For HD and Towing use 4R100-HD2-Tugger. Assistance Video Special Instructions: Requires transmission removal for proper installation. Installation recommendation: Professional technician Transmission removal necessary: Yes