A power distribution assembly integrated into the lower engine housing of an internal combustion engine, the assembly having a drive train with a T-box output configuration and power take off driven by the crankshaft of the engine. The drive train may power the input shafts of a pair of independent, variable drive transmissions. In one embodiment, a single actuator engages a manual clutch/brake mechanism that controls the output shaft of the power take off. In other embodiments, an electric clutch affords control of the power take off mechanism. In further embodiments, a hydraulic clutch/brake assembly allows control of the power take off, and an additional hydraulic clutch assembly may be used to control the outputs of the T-box.