In parallel with the F8U-1s and -2s, the Crusader design team was also working on a larger aircraft with even greater performance, internally designated as the V-401.
Due to extensive changes as compared to the F8U-1, the F8U-2 was labeled by some as the "Crusader II", and as a result, the XF8U-3 was officially labeled "Crusader III."[REF] .