from your name it sounds like you got a 77 lincoln. i have a 79 mark and i put some 18s on it with 245/40s and they were a little shorter than stock. if you still want it to ride nice get somthing a little taller. lie some 235/45s or 235/55 vouges. 30 series are wayyy to short, for me at least. 35 series are like rubber bands.