660 of course. I have the evo 16G amongst other mods and i'm glad i went with the 660's. a place on ebay sells the 660's for like $300 or so. great injectors and i've had them on my car for 3 months without a single problem. the SAFC install write up is hard to find. try this email address. lucasenglish@yahoo.com his name is lucas and he has all the write-ups stored and is basically a guru when it comes to mods or tuning. helped me immensely when i was building my car. good luck! -Scott