my akro evo from my 01 1000 bolted right up to my 03 1000. It actually fit better on the 03 1000. On the 01 it touched the plastics below the rear sets. On the 03 it had plenty of clearance.
I also bought a ti force for a 01-02 1000 and put it on my 03 1000. Fit great. I also think if you go to ti force website it lists their full system for the 01-04. Some dealers and distributers will tell you their is a diferent system for the 01-02 and 03-04.
I know several people that have put a 01-02/03-04 akro on a 05 1000.
