Good little design. I would have used them when I built mine but at that time they only had a frame to fit up to 7hp and I wanted a 13hp. They used to only sell with subaru/robin motors that use an over head cam. Now they use cheaper motors. They used to use "lovejoy" style couplings that are used in industrial apps instead of "U" joints as they gave a little cushion to the drive train when the prop hits something. Not sure now. I have seriously considered replacing my beavertail steel frame with one as it would drop about 50lbs off the transom.