OK - now I remember - the P-77 had a Ranger V-12, I thought it had a straight 6. From "Wiki," here's a list of aircraft it was installed in, the Seamew and Gunner were the only production aircraft that had this engine.
V-770-4
installed in the Vought XSO2U-1 Scout
V-770-6
installed in the XAT-14 Gunner prototype, intended for the Ryan SOR-1 Scout
V-770-7
installed in the Bell XP-77 light-weight fighter prototype
V-770-8
installed in the Curtiss SO3C Seamew Scout
V-770-9
installed in the XAT-6E Texan prototype
V-770-11
installed in the Fairchild AT-21 Gunner
V-770-15
installed in the Fairchild AT-21 Gunner
SGV-770C-1
tested in the Curtiss XF6C-7 Hawk Fighter-Bomber at 350 hp
SGV-770D-5