different. I made a template of the original rudder head from a side of manilla folder (light cardboard). I laid this template  over the new rudder head, matching the pivot holes, and marked the original profile on the new rudder head. There was a  thin arc over the top and down the front of the new rudder which was larger than the original. I used a jig saw with a  metal blade to cut away the extra material and filed the edges smooth. When I put the new blade back in, it worked  perfectly.  If your new rudder doesn't yet have the pivot hole drilled, then a template made from your original rudder head should  help you locate it just right.  As you can see, my plastic rudder sleeve came with a hole in each top corner. The back hole is for the up haul line. I use a  shock cord hooked into the front hole and looped over the hinge and back to the hole for a down haul. The shock cord isn't  in the picture.  110