03 440's were the easiest to trail convert. i used the stock needles on my 03 but changed clip position. put a 10 gallon tank on it, longer pick up in the tank, low compression heads, change base gasket depending on what's in it, change jets, and unplug the timing switch.
the track, and gearing is what makes the sled bad on fuel. lots of fun in tight twisty trails or ditches but the wide open trails they get left behind. on my 03 i would get 50 miles to a 10 gallon tank on the set-up i had. brutal but the most fun ive ever had on any machine!!
tons of info on dootalk.com in the 440 race section.