Can anybody confirm that this is true? If it is, the 04-06 route would be a lot cheaper since the spring is $55 cheaper. Also, I have the set off my 06 clutch and I already have the Graves Kit installed on my 09 so I have a spare or maybe I can help somebody out.
Here's the thread I read the info from and it says the parts are the same between gens, but the 07-08 costs more for the spring. I'll have to PM the member to see where he sourced the info, unless somebody can confirm and just post it here.
Now that I'm back from Japan, I was swapping the YEC springs back to stock so I went ahead and made a comparison between the Graves kit and the 06 parts.
They are essentially the same with the exception of the clutch fiber color and the thickness of the cupped judder spring. The 06 cupped judder spring is thinner than the one with the Graves kit but is cupped more so they seem to cover the same overall dimensions.
Attached is a pic of the Graves Kit on the left and the 06 R1 parts on the right. I am now running the 06 parts in my 09 and put the Graves kit up for sale.