I visited some young hooligan friends in Portland over the weekend. Over the years they have been putting 240D flywheels from engines with manual trans. on 300 motors and converting them. I don't believe that any of the conversions are more that 3 or so years old. Since the engines have dynamic balancers on the front, would the only issues be longevity of clutch. The tranies seem to be pretty durned bullet proof!