I had the opportunity to run a 150 back to back to a 160. The 150 was a super-corsa DOT tire and the 160 was super-corsa slick (pirelli). Ran the 150 for a few laps, pulled into the pits, whipped off the 150 and on with the 160 (got to love the 28 rear end!). there seemed to be no difference. I believe I did raise the front to compensate for tire diameter difference. Now the 120 sized front.... don't do it!