The 737 is Boeing's only narrow-body airliner in production, with the -700, -800, and -900ER variants currently being built. A re-engined and redesigned version, the 737 MAX, is set to debut in 2017.oeing's BBJ3 is based on the 737-900ER. The BBJ3 has 1,120 square feet (104 m 2) of floor space, 35% more interior space, and 89% more luggage space than the BBJ2. It has an auxiliary fuel system, giving it a range of up to 4,725 nautical miles (8,751 km), and a Head-up display.