Just because you are using a prop drive does not mean you do not need down or right thrust. You are exchanging high RPM,small diam. prop disc for low RPM, large prop disc with lots of pitch. This means more torque, and gyroscopic forces operating on your nose. I would go with the right thrust and down thrust that is recommended. you may have to add more right thrust due to greater "P" factor due to the larger diameter prop. just watching your six Bro. By the way, have you asked Joe what he thinks?
Gary