Frank: I am probably the only one who has this problem, but once you are over 40 you forget things. I don&#039;t remember all the details on this but in the winter of 63, (now if I was not 40 I would not remember that) when the Columbus branch had their dealer thing for the new products for 1964 they announced the new look for the 770 and 550 (Checkboard grills, etc.) They also anounced if you had a tractor(s) in your inventory and you wanted to update them they would have kits with the new grills available. I do not know if the Cockshutt sides went with the 770 kit or not. We did not have any in inventory. Therefore we never got any kits. So I will go along with Larry&#039;s statement on the change for 64. This also explains why some older 770 and 550 tractors have the new style grill.