It's really not that big a deal if you are careful and watch what you're doing. I planted for a few years with a JD 7240 drawn 8 row 30" planter and shelled the corn with a 6 row 30" head. About the only place I had any issues was on end rows occasionally planting around curves. And not very often. This was years before we had any type of guidance system other than the planter marker.