Cummins NTC400 Big Cam 2 6 Cylinder Diesel 400 hp Engine, Engine Brake, Eaton Fuller RT14615 15-Speed Manual Transmission, 18000 lb Front Axle, 44000 lb Rears, SSHD Drive Axles, 4.56:1 Axle Ratio, 36 in Flat Top Sleeper Cab, Bunk Heater, Aluminum Wheels, 425/65R22.5 Front Tires, 11R24.5 Rear Tires, Big 6 Spring Suspension, 250 in Wheelbase, 97 in Cab to Axle, 181 in Cab to End of Frame