how so? its only a slight stretch. not like a drifter style stretch

 

Since a 600rr rear is designed to hold a 180/190 but still hold a profile that will allow for great handling I'm guessing the rim size is much different than a F3. So I'm guessing the 600rr rim is much wider and would have trouble fitting an F3 rim.

Now a 600rr front might work. Now if you have time and a friend with a 600rr you can always swap rims out to see if it will work.

 

so i think its going to be a-go with these wheels. i will put a 170 tire which is a nice compromise. im running a 180 tire now but would like to get better handling and maneuvering which i think i would with a 170.