On my 02 I milled the head first, (keep in mind I am at altititude) this produced a small benefit in lower mid power, I didn,t notice a lack of over rev (not that much of a revver anyway) and I switched to a 50/50 race gas mix to avoid pinging(a preemptive strike on my part, I didn't try it without the gas). The best gain I got was from cylender mods, the base was lowered (I don't know the numbers but the same thickness as a stock base gasket) and the ports reshaped, the bike pulls MUCH harder through the low and mid ranges, I think it signs off a little sooner on top, but it may just be that it gets to that part of the range much quicker, the bike is still smooth for a 2-stroke, but makes power in a much more practical rev range (for me). With the stock cylinder and head mods I still went to a 49 tooth rear with the cylinder mods I went back to stock gearing and it still pulls better out of turns. Hope this helps.