The three digits represented the last three digits of the transmission part number. It was on the "Broadcast" or build sheet. The transmission line, where I worked (at Dodge) was part of a sub-assembly line or loop - not the Main vehicle line. This sub-assembly "loop" and another, "dressed" the engine and mounted the transmission before it went to the Main line.Usually all of them in a rack were the same last three numbers, if it was a common transmission. Then one rack mixed to make the quantity on the shipper. I was in Shipping and Receiving mostly and I could count the 680's (or whatever no.) in the rack, to make sure that showed on the shipping bill, before signing it as received. I would guess the numbers were 3-4 inches tall. I think the colors varied with number.
