From Simland CR8EIX is for 950 carbs LC8 not for 990EFI.... A small reminder: MODELS XXXXXX (IRIDIUM) 950 carbs NGK CR8EK (CR8EIX) 990EFI <- '08 NGK DCPR8E (DCPR8EIX fixed cap so not suitable or DCPR8EVX removable cap) 990EFI <- '08 DENSO XU24EPR-U ( IXU24 removable cap) 990EFI '09 -> NGK LKAR8BI9 .... without to change or modify something at the bike or the plugs VoilĂ ..... or I have no idea what is available but this is what info I have saved.
I run iridiums in my 950. I spoke to Bosch about the cr8ek design - simply it is to extend the wear life with the 2x grounds - does not help performance and is basically an old design before platinum/iriduim was available and cheap enough. The iridiums will last longer and perform better.