I remember seeing a vid of one pulling. It was pretty funny. The vid was about 9 minutes long and before the IDI came on around the half way mark there were a bunch of Cummins, powerstrokes, and duramaxes pulling. Then this beat up old IDI comes on, and gets a full pull or something close to it. Then when the truck starts slowing down it starts smoking alot, and then it complelty stops and he tries turning it off, but it started running on oil or something. It actually did pretty good.
I dont know the rules to sled pulling, but basically I think you just need some super low gears, say 5.88's, some fricking wide tires with tons of grip, lockers, and at least mildly tuned IDI (turbo, pump turned up, ect...). But maybe they wont let you run those gears or something, so I might be wrong.