hardrockminer wrote: The billett aluminum is the one with O rings. I've never tried it.
The black plastic one is indeed OEM and I recommend it. I've bought several sets and had no issues. Prior to installing you need to immerse them in gasoline for 24 to 48 hours. They will absorb the gas and swell a bit, making them a very tight fit.
I know it sounds strange that the plastic "T" would swell after being soaked in fuel, but I do believe it. Years ago I brought my bike into my basement over the winter so I could do some work on the forks. I first removed the fuel tank and put in in the garage and drained the carbs so I didn't create a fire hazard. Of course this resulted in the plastic "T" drying out. In the spring when I took the bike outside and replaced the tank the "T" leaked quite a bit when I turned on the fuel. I definitely was not happy, and I searched the internet for a new "T" but couldn't find one. About a day or so later when I turned the petcock on again I saw that the "T" had stopped leaking . That was 12 years ago and it has not leaked a single drop since. Ed