a heavy single disc clutch will be kindof in or out. They don't slip much, and any slipping is really hard on them. Heavy single disc clutches are hard on drivelines as well. They take up all the slack in the driveline, from your timing gears to the play in your rear end, RIGHT NOW. Not very forgiving. Consider a dual disk or another clutch that is rated more for the power you are running or the power you are after. Don't buy the heaviest clutch you can find. You will hate it.