I have 2 ZTR's that are Super Z pre hyper D XR7, I have a job that has real steep inclines and they are adding more work to it this year. I have been using the 72 and found it to be great because it is wide and does not want to flip over but they are adding much more area to be cut that is likely to be wet and a 72 gets stuck easier than a 60. I like 72's because they are fast and stable on hills but do get stuck easier and the drive is strained more, I am going to update 1 mower with repower with a BB motor and going to put high torque wheel motors on it with some kinda new tire arrangement 26's or rib 24's? or possibly dual 22's? but have not used the 60 in years because I like the 72 better for me but am wondering if moding the 60 out might be a better choice for a mower doing wet areas with steep inclines. This is interstate exit areas that only gets cut once a month and are real steep. Any input from people who use both 60 and 72 ZTR's would be great and know of the best mower to do this. Thanks for any help.