There's a farm north of here that runs 18's on 22's.  pull sprayer and plant with it.

I got 18's on my 765 and have pulled a 7 shank disk ripper, pull a 6 shank inline ripper with dry box, and a couple disks.  always around 3 to 4 % slip or less except by the driveways and some end rows. 

Front end weights are a must for heavy tillage with a track tractor.  I forgot about them one time and went to inline and put in ground and 16 % slip, alarm going off I was like, what the heck!!!  Duh!!  back to town to put the weights back on!

Some times a 835 would have been better on the inline ripper, I like the smaller frame tractor better.