In Reply to: Tires for 641 posted by Tom on March 03, 2019 at 19:25:04:
11.2s are one size too small for a 641 but it sure won't hurt anything to run them.
I had the same deal once - a real nice pair of Firestone 11.2s that I ran on a 3000 for a while. That tractor should have 13.6s on it so it looked kinda dumb and when plowing I had to be Quick on the clutch or it would dig itself right down to the drawbar in short order. I eventually bought/ traded them for an equally nice pair of 12.4 Firestones and have been running those for most of 10 years now - one size too small.
I say try them and see if they work for you.