I'm assuming this is a 3020 that is from the late 60's or early 70's abot 60-70 HP? The best way is to widen your rear wheels out to where the center line on the tires is in line with the outside edge of the cut of the hog. Every pass leave your tire just outside of the standing grass from where you just cut.
it will also be easier if you widen your front tires out to where they are on center with your rear tires.
Above the transmission (on a 2020) there should be a mark dead center of the tractor to hold the end of a tape measure, alot of people don't know what the slot in the center is for till they read the manual and it tells them in black print. Asuming you straddle the trans and it's not a platform.