I bought some NOS 6F1945 rod bearings, and some are in boxes and some are in wax without a box. In 2 of the boxes, they are marked upper and lower in ink, but I really can't tell any difference between them. In one of the boxes, they are not marked upper or lower. I never removed the wax from the other bearings. On 1 of the waxed bearings, there is a tag on the back and it doesn't say upper or lower on it. What's suppose to be the difference. Is there a way to tell. Does it make a difference if they get reversed at all by accident? Does anyone know? They should have had that stuff stamped in the back of them.