I am also a new 2520 owner with R4's. My tractor was a dealer demo model, the inside of the lugs of the rear tires are knicked up from the 3-pt arms not being adjusted correctly to limit the side to side movement in the hitch. The tractor had a 3-pt mower on it when I looked at it at the dealer. Must have mowed a lot of side hills and the mower would swing to the downhill side and the arm would rub on the tire. I purchased an I-Match with the tractor and adjusted the arms for minimal side to side movement. I just got a set of chains a week ago and put them on the tractor last Saturday. My chains were manufactured by Peerless Chain in Winona, MN. The bag they came in said "Truck Chains" on it, and are supposed to be their Heavy Duty chains. I had the tractor in my shed on concrete with a floor jack lifting up on drawbar assembly. Both rear tires off of the floor, bucket down flat, real stable working conditions. I installed the chains, and felt that they fit well over the tires but the length was a little long. I have since picked up some "cold shuts" to install and shorten the chains without cutting any links out. I had plenty of room between the 3-pt arms and the chains, there had to be over an 1 inch of clearance.