I don't know much about these as I got them from a garage clean out.  Based on other listings, it appears to Pair of Used Rear Wheel Clamps for Farmall Tractors as shown.  They have manufacturer's stamping of 363016-R1.  BASED ON MY RESEARCH, THESE SHOULD WORK FOR 300, 340, 350, 400, 450, 460, 504, 560, 656, 666, 686.  YOU WILL NEED TO VERIFY THIS FOR YOURSELF!  Both appear to have varying degrees and signs of wear, use, and abuse and I blasted the area of the manufacturer's stamping to may it easier to read.  However, plenty of life left as used parts.  Would be great items to replace those missing ones or for that restoration.  Please see the pictures as they are part of the description.  Again, check to make sure that this will fit your application.  What you see is what you get.  Look the pictures over and judge for yourself!

AS WITH ANY ITEMS, NO RETURNS ACCEPTED.  Item is for sale locally, so I reserve the right to end listing early.  International buyers through E-bay's global ship only.  It will take a few days to get item shipped.  Please let me know if you have any questions.  Thanks for looking!