The performance of the -A model was basically the same as with the original engine.
During the 1920s the Air Corps traditionally assigned a new designation to an aircraft based on an engine change, for example the Fokker C-2 & C7; however, beginning in the early 1930s this practice changed.
Instead of assigning a completely new designation, the Air Corps began assigning only new model identifiers (A, B, etc.) to indicate an updated version of an aircraft.