The new engines greater weight required the fuselage section in front of the wing, to be shortened 5 inches, to keep the CG within limits. It's exhaust outlets were relocated and more vents were added to the cowling to eliminated carbon monoxide concerns, which was detected in the early versions. The U.S. Navy had to wait an extra six months for their aircraft, as the first production F2A-2's were sent to Belgium as the Brewster 339B. It was not until September 1940 that they started to receive their Buffalo's with Fighting squadron two (VF-2) and Fighting squadron three (VF-3) re-equipping with the -2 in early 1941.
Operating from the USS Lexington and USS Saratoga, the new Buffalo's replaced the old Grumman F3F biplanes, then still in use. VF-2 modified all of their Buffalo's by eliminating the tall fuselage radio antenna mast and replaced it with a short stub mast bolted to the left wing. The F2A-2 Brewster Buffalo provided introduction to high speed monoplane fleet operations, and continued in service with the U.S. Marine Corps and as trainers until late 1943.