My friend Ryan sent me a bit of a doozy (which he then helped me figure out).
"What shift star and detent/spring are the best?"
Well it turns out that the ones you want are 05+ for all 1g and 2g bikes. They are as aggressive as the factorypro kit and cost much less.
The 05+ star has bigger lobes, the spring is stronger, and the detent arm has bearings rather than a bushing
left is 05+, right is 99-04
05+ note the bearings on the detent, an extra coil on the spring (blue not yellow), and more aggressive lobes on the star, and the #3 printed on the detent.
99-04
The part numbers you want are:
PLATE, GEAR SHIFT CAM
25381-19F10
same 99-04 stronger 05+
STOPPER, GEAR SHIFT CAM
25350-35F00
same 99-04 stronger 05+
SPRING, STOPPER ARM
25355-35F01
different 99-02 vs 03/04 vs 05+ which is stronger
A lot of other parts in the shifter arm overlap between all years. and mostly dont matter.
here's a spreadsheet of the parts for the various years and compatibility
https://docs.google.com/spreadsheets/d/1hKbU-KE6p6R6rakMttDcvKStRJXlGV9WswL8jTEz8Pk
