Description Originally offered as a direct screw-in port adapter for the J Series cylinder head water outlets, but becoming a useful connection for anything that has an M28 x 1.50 thread and seals via a crush washer. Recently used on the back of the B Series blocks for crankcase ventilation and to feed coolant into B and H Series cylinder heads for those running dry deck blocks! NOTE: Requires the use of the Honda crush washer (90401-PR4-000).
