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
or I have no idea what is available but this is what info I have saved.