86 series tire sizes. in General IH Posted April 17 Hey all , I recently bought a 986 with plans to narrow it up and pull my corn planter and sprayer with it. 30 inch rows. Unfortunately the tractor has 20.8-38s on it and as well as I can figure you cannot get it narrow enough. On our hills I need to be 84-85 inches total width. can an 86 series go down the rows with 20.8’s or should I buy 18.4-38s?. what about step up rims and going to a 16.9-42? Would that clear the fenders? any insight is welcome!!