The Sun Coast 6188248 48RE Valve Body for your 2003-2007 Dodge 5.9L Cummins is designed to enhance transmission operation, and durability. In your transmission, the valve body controls gear selection, line pressure (clamping force), line rise (meeting torque demand), converter mode, flow and pressure, along with shift timing and quality. The Sun Coast valve body addresses all of these areas to increase performance in your transmission, allowing for crisper shifts, enhanced converter operation, cooler operating temperatures, and increased lube flow. Full time converter feed assures lube flow while in the park position and under high throttle conditions. Torque converter clutch loc-up can be achieved in all forward gears when used in conjunction with a controller. This feature is desirable for optimum exhaust brake operation.