Tyzer, Just installed one today and will give you some ideas on this. On Page 9 of the installing, Step 5 it shows you where to drill the holes. The number 2 distance is actual measured from the center of the last holes, then down, on the frame. The picture is misleading where to start from. This 1-49_64". Measure and drill the hole to the front of the header first. Measure the 1-49_64" down on the back part of the frame. Then mount the linkage loose to the top bolts and to the hole you just drilled at the front. Use a center punch to get the exact drilling for the back bolt. I used a 17_64" drill to give you a little room for fitting. One more thing, it you have a 1660 you will have to purchase an additional adapter that turns the current around from the potentiometer. Part number is 87412210 about $12.00 Hope this helps.....any other questions just ask. Jack in MN