Adrian
Go with what Wozza suggests. I run with IK22 on the s/c & no problems. Heres the tech blurb
"DENSO Iridium alloy consists of Iridium and Rhodium. And DENSO was awarded by SAE, Arch T Colwell for this new technology."
And a decent site for the techno there will be other places to buy !
Denso
Cheers
Bobby