My 1992 Case SK backhoe came with 17.5 on the rear. Is there an advantage or disadvantage to going with the 19.5 when I need new tires?
I dont see any advantage. Just going to loose clearance between the tire and the cab
2x4 or 4x4?
It's a 2 wheel drive
A little more available traction and you won't sink as much (think ruts) into soft ground conditions with the wider ones. I have had both sizes on my tractor and would stay with the widest ones I can put on it. And you can select how many plys are in them if you are buying new ones. I don't know if you could put chains for snow on with the wider tires. You may find this an interesting thing to read. http://case580kbackhoe.com/