You car could rate lower depending on the dyno you were on. Either it wasn't a dyno jet or your dyno jeft creates more loss. Not a big deal is you kill the 00/01's

The 98's had a weaker intake cam (and I suspect slightly less agressive fuel maps in the ECU). THis accounted for my 1998 R making 160 stock on the same dyno my old 2000 R made 168 stock.

I would not stress it. Just use the same dyno for power comparisons or if you have an opportunity try a different dyno to see what sort of power it makes.