What was the problem with your odometer? Usually, it is only the gear. I've had some people fry theirs by hooking up the tach, but that's operator error. What I'm getting at, is why not put yours in the new cluster, and see if it works. Other than that, I've never taken them apart to lower the miles. I've put gears in the 850 ones, and spun 'em up to actual mileage with a screw drill, but I don't think that'll work backwards...something will break.