Anybody here ever have one of their differentials modified by Metric Mechanic for infinite variable lock-up? Jim Rowe bent my ear on this a while back - something about recutting the gears to allow a pin to float - but I do not recall all of the details. This is like having 100% lock-up when you needit and Zero when you don't so your tires don't prematurely wear out. Quite costly but less so than a Quaiffe? Did it really work? Praises/Denouncements?