This is the one and only fluid release auto shift transbrake for the 4L80E transmission. ECM tuning not required. Deep pan not required. Transmission brake can be applied in any forward range. Will shift automatically in D2 and D3 positions, or can be placed in D1 range making it a full manual valve body with the driver controlling shift points. Redesigned oil circuitry provides super positive gear changes, increased torque capacity and instant transmission brake release for the ultimate in efficiency, performance, and durability. Each valve body is dyno tested. Includes complete valve body with new internal wiring harness, all new solenoids, and new pressure manifold. Fits 1996 and up models.