I used a magnetic angle indicator that I bought from Harbor Freight for about 4 bucks. Bolt your mounts up, set the motor in, put the angle indicator on the u-joint's, set your angle to between 2-4 degree's. Mark your holes in the stringers for the new mounts, pull everything out and drill your new holes.Fill the old holes with a 3/8" dowel and glass them over.It worked for me!