K-Tuned KUW-20D Filler Neck Upgrade - 16AN Fitting - KUW-20D-F16Applications: Filler Neck Upgrade for KUW 20D N02 Note: * There is a fitment issue with the K20 upper coolant housing and Jackson Racing Supercharger. We have brought back our K20 housing w optional filler neck. We have made some changes to the design. We have kept a lot of the basic features like the 1 8NPT temp sensor port and recirculation fitting. The housing seals to the head using an o ring to ensure no leaks. We supply the mounting hardware and