According to [aviation-history.com][1] the design never left the drawing board. 

>  In 1935, the US Navy ordered the XF4F-1 as a backup to the US Navy’s first monoplane fighter, the F2A-1 Brewster Buffalo. However, data from the Buffalo demonstrated that the biplane fighters could no longer match the performance of the monoplane. It was now apparent that biplane fighter's days were numbered as the XF4F-1 performed no better than the re-engined F3F.


  [1]: http://www.aviation-history.com/grumman/f4f.html