Contract 99036, 18 April 1942, for 1,150 FM-1 (311 for RN) with P&W R-1830-86
Contract NOa(s)-227 (99036), 31 December 1943, for 4,100 FM-2 (340 for RN) plus another 1,423 in 1945 of which 746 were cancelled, with Wright R-1820-56/72W in 1943, -72W only in 1944, -56W in 1945, a total of 4,777 built.