6AN center port (for rail)Applications: K Tuned fuel rails only Note: *Does NOT work with none K Tuned Fuel Rails Here is another optional fitting that can be used with our K Tuned Fuel Rail. Available in 6AN or 8AN, the center port fitting can be used as either a feed or return depending on the fuel demands of the engine being used. Show and all motor cars with up to 300 whp will like the clean look this fitting gives because the fuel feed line can be hidden or 'tucked' for