People seem to overthink the planter width. It's simply the row spacing times the number of rows. I presume you have 8 rows that are at 30" spacing. Your track spacing would be 20'. If everything would be mounted correctly on the toolbar, the dimension form row 1 to row 8 should be 210" (7 x 30). So if you're off on that dimension, you're going to have a tough time getting your guess rows right on 30". But let's say you move the row unit(s) to the correct place on the toolbar (which is the first thing you should do if you want to get the guess rows correct), then set your track spacing at 20', no more, no less. Find a level place in a field and set up a straight track. Put the planter down and drive a ways. Pick up, turn around, drive right over the same track, and stop (make sure to go far enough to let the planter get lined up behind the tractor). First, make sure the tractor is in the same tracks (if not, there is an incorrect offset entered for the tractor itself). Second check to see if the rows on the planter line up with the previous pass. If they don't, your problem is in your Planter offset. Enter a value in the planter offsets that equals half the amount of your error in the OPPOSITE direction that the previous pass is relative to the second pass (as you are looking forward towards the front of the tractor). So if the first set of rows is 4" to the right of the second set, you'd enter a 2" offset to the left in the planter offset. If you're still having trouble maintaining an acceptable guess row spacing, you would likely need implement guidance to eliminate sway/draft in the hitch. I probably mentioned things you've already tried (I didn't read the previous posts), so forgive me for repeating and/or telling you things that you already knew, but I've seen a few posts on how to measure planter track spacing lately, so I am throwing my two cents worth on the subject out there, take it for what it's worth to you. Good luck getting it better