My fuel rails are -6AN threaded with no internal flare. Will a std flared -6AN male/male adapter seal adequately? I do not believe it will and think that an o-ring specific fitting is required for the fuel rail side of the adapter but am getting advise suggesting that neither a specific adapter nor an o-ring is required. Possibly an o-ring installed onto the male/male -6AN adapter works? Desire responses from those who've successfully installed port fuel injection systems.