In mid 1942, Grumman respected it had a need to concentrate on the manufacturing of its amazing F6F Hellcat fighter, such that it contracted along with the General Motors business to make the Wildcat in designation FM-1. many which went along on Fleet Air supply while the "Martlet Mk V." General Motors next developed a much better variation, called the FM-2 , which was powered by a Wright R-1820 engine with 1,350 horsepower. It showcased a taller straight end versus FM-1.