P-40M - similar to the P-40K, with stretched fuselage like P-40L and powered by an Allison V-1710-81 engine giving better performance at altitude. Two small air scoops just before the exhaust pipes. It was also supplied to the Commonwealth air forces as Kittyhawk Mk.III.
P-40N-5 - revised cockpit canopy, 6 wing-mounted machine guns, and wing racks for bombs or drop tanks (1,100 built)
P-40N-20 - with more power engine V-1710-99. (1,523 built)