How much offset do you need?
The 60" is made slightly offset to begin with - in other words the pins aren't centered on the implement. I didn't realize this at first and it used to drive me crazy when I first got mine. Once I had it centered between the wheels with the 3ph I could never get it to sit square without having the PTO shaft set at a slight angle.
When it is set square (tiller spool parallel to rear axle & PTO shaft perpendicular to rear axle) it doesn't quite cover my left tire, but completely covers my right. For me, this is almost perfect as it allows me to get in and out of some tight areas, and if I work from the right to left I can till without leaving any tire marks until I do the last row.
-Jim