I don't think NGK distributes their DILKAR7M8 plugs in North America. I got mine from a dealer and put them in at 40k. Improved pep. Do it. It takes an assortment of 8mm & 10 mm sockets & end wrenches to loosen the plate that holds several relays and other gizmos that sits above the plugs. The spark plug socket is a 14mm...one more new tool added to my box.
JEGS will have them in stock, ETA July 21.