Centering of plow to c/l of tractor will balance the pull on the tractor equaly to the driving wheels . On a 2 bottom plow at 12-14" furrows on a 35 Fergie size tractor the top link usually not run straight that is why wheel track settings front -rear inside measure need to be the same. [I prefere the front wheel 1-2" wider ] When both lower arms converge at the same angle [relative to c/l of tractor] you are not far off. Adjustments to disc culters draft bar position [l-r] rotation of bar alignment of last furrow landslide [bent] has a direct effect on plow alinement to tractor. Always consider the landslide to a rudder on a boat 1 degree off will turn boat [l-r] same with a plow; disc setting is critical on last furrow along with ware and side movement in spindle . cammax
The JD book on plowing, suggests the tractor settings from center of the drawbar to the inside of your right rear tire be 23 1/2" for 12 inch plows, 25 for 14" and 27 inches for 16". Of course, some minor lateral adjustment can be made on the plow cross drawbar. Ken Sweet