We cut the centers out of some rims recently on a 2615HST Mahindra (like a Cub) and rewelded them in the rim like we wanted, adding about 2" clearance per side. It took longer than I expected, but is a nice fix.
Jim,
I was on the same quest as you some months back for my Cub.
What my problem was; locating "cone seat" lug bolts in metric thread. Never did find any long enough. (3 - 3.5")
If yours takes that type bolt and you find some ; can you let me know ?
There are some other options but none have been viable for me.
GrayBeard
I'll let you know what I find or my tractor. I did find a guy that can make me a set for $80.0. only need 1/2-3/4" for my chains to clear. I thought I needed more. Once the tensioners tighten up the chain the side chains just rub lightly on the brackets. I will keep my eyes open for the type of bolts that you need. have you tried a Google search for them?