With our Heritage JrFueler,we only have 1/2" clearance with no problems, keep in mind the D2585 GY are very light, 22.6 lbs, and grow with RPM, and the tire gets high from the sidewalls, so at speed the tires pull away from the body.
BTW my GoodYear Special Order of D2585's, 31x12x15 are in stock now and we are shipping this week.
Call me, 800-624-3803, or Email, jchansen60@gmail.com, if you would like any.
My next GY Special Order they are building now is D1288, 33x12x15 and should be able to ship next month.
Jon Hansen