There is another issue about switching to gear drives in the new motors and that is runout. It is now common for brand-new motors to have .005 runout, which used to be cause for concern. Now it is not considered a problem until .015 or so. That is not a good situation for running gear drive cams. Basically, I have been told my extremely knowledgeable people that there is no reason to switch on motors 2007 or later, and you may end up damaging things as well.