the NGK irridium range 7s are just as good mate, and all it is is they have a single electrode not the 4 way slit one. The temp range and material is the same, just the electrode design is different.
Sparkplugs UK NGK Champion Denso Sparkplug, Glowplug and Lambda Sensors do these for about £30
50k miles on a 15% reduced pulley car running way over 200bhp ... and never had a set with any daage showing or cylinder temp issuies or detonation.
