'99 would not have the adjustable front cartridge forks or adjustable rear shocks from the factory. Also different front brake calipers. If you plan to change those items, not much difference otherwise except possibly cam bearings, depending on early or late '99. If you don't plan to upgrade the suspension, keep in mind '00-'05 FXDX suspension is definitely an upgrade vs. '99.

 

As stated above, the suspension and brakes are not as good on the 99 dx. The front brake is brakes are single piston / floating caliper. Fork lowers have different caliper brackets than 2000-2005. The wheels use timken bearings instead of sealed. Since it has motor work done, would would hope that the rear cam bearing and outer gear have been upgraded. All TCs had questionable rear cam bearings up until mid 2000 production (Dec 99 mfg date) so if you go with the 2000, it should be checked.

 

Found an 02 as well. Any major differences between 00 and 02 besides the cam bearings/tensioners?