The race spec ones are likely to have the different disk fitment too, which means different disks, calipers, and probably forks and yokes too!!!
There is no speedo drive recess, so there needs to be a spacer machined to fit the gap - if you were to try them in standard forks - and that's forgetting about the issues mentioned above.
If this is an ebay deal, then you'd have no come-back on the guy as he did list them as race-spec - beware!!
Tim
[Edited on 1-7-2004 by Rattler]