Yes the '04-'05 has a 17/39 setup with a 50 series tire. The stock setup is good for 180mph or so.
The '06-'07 10R has a 17/40 setup as opposed to the 39 if I am not mistaken. I also think it would swap right onto the '04-'05? The '08-'09 10R setup is 17/41. So if you could get your hands on an OEM rear from an '08 you would already be +2 in the rear...assuming that the rear sprockets are interchangable. You would also be better off going down one in the front instead of +4 in the read IMHO...-1 up front doesn't require a new chain which would be needed if you go too big in the rear, but you still accomplish the same gearing change. You could try the 3nd gen rear sprocket (+2) and then go to the 16t Z1000 (-1) up front. Should make her real schnaaappy! But I don't know about the chain size...I believe that the OEM 1st Gen is a 108 link? and the 2nd Gen is a 110? Not sure of the 3rd Gen 10...
I have read some favorable results about the 55 series tire as opposed to the 50 also...and it should also widen it out a bit by going to the 55 tire...and raise the rear end up a bit and should help with better turn-in. You just need to have a slightly longer chain to set the tire back a little further, so the 55 tire doesn't rub on the hugger...or just take the hugger off.
If you decide to go to a 16t in front, you would be better off getting the front sprocket off of a Z1000, as they have a rubber insulator and are quieter like the aftermarket sprockets.
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