I'm not exactly sure but I think the 99 was there most powerful H.O., not sure if that's the sled your looking at (98 H.O.). For what it's worth I've rode my buddies 97 a few times, very nice sled for a scud.... He hasn't beat my XC 6 in a drag....yet but overall a good ride. I think he's got 4 grand on the odometer, with no major problems.