My sons, ages 9 and 11, decided they want to try pulling in the youth class at some of the local pulls. I just purchased a C160 for their first pulling tractor. They will be pulling in the stock 900lb class. They can use up to a 23x10.50x12 tire. Any reccomendations on tires? Can I mount 23x 10.50 Ags on the stock 8.50 wheels? I'm also looking for input on a variable speed pulley. I also believe the C160 has the weaker 4 pinion rear which I wil probably use until it breaks. What is the approximate weight of the C160? Thanks for the advice, I enjoy looking at all the amazing tractors on this forum.