neat idea, never saw these before. pricey but you'll save money on crush washers and if you're in the market for a new plug anyways:
Link here
Manf Link
http://www.demon-tweeks.co.uk/Produ...m=Base&utm_campaign=Oil Coolers & Accessories
Link here
Manf Link
http://www.demon-tweeks.co.uk/Produ...m=Base&utm_campaign=Oil Coolers & Accessories