I'm gathering materials to build a land plane, the type with two long runners and two diagonal cutting edges, like a Woods GS72C or Land Pride GS1572. It will be used to maintain 1/2 mile of stone/gravel/dirt road. I have a 4120 (43hp) and my rear tread width is right around 73". I had been planning on making the grader 72" wide, plus the width of the runners. Now I'm wondering if I should go 84". I'm looking for input from anyone who has used one, is the extra width really necessary to cover the tread, and will 84" be too much for the tractor to pull? I'm just thinking it may be nice to have a few extra inches sticking out the sides to work the edge of the road. Would it be a bad idea to offset the hitch 6" to one side?