40-2090649 Head gasket, Hercules model G1600 engine. Original part number was 40-209063440 2090649 Head gasket used on the 1600 series Hercules engines, Gas types. Old part number was 40 2090634 and has been superseded to the above new number This will be item number 12 in the Hercules drawing. This engine was used used in numerous lines of forklifts and generators including DMT, Caterpillar, Clark, Komatsu and Daewoo.