70 dart vinyl tops

I know this , not asking about 4 doors and haven't brought it up . Asking about 2 doors and why classic and legendary and others sell 3-4 different measurements for 2 door . From what I've read it's the seams on top but k can't get that confirmed anyhwre and if that's what they mean which measurement is best ? Or more correct ?
I replied to the wrong comment. apologies