View of workers assembling crankshafts at Plant 4, Engine Assembly, Bldg. 20, GMC Truck & Coach plant. Printed on front: "GMC Truck & Coach Division." Handwritten on back: "Plant 4, Engine Assembly, Bldg. 20, third floor. Crankshaft & flywheel & clutch assembly to crankshafts. Factories--GMC, ca. 1943."