In Bob's book there is a mention of when that dimple left the production line...Side mount radiators do not need it but it took a while to drop that feature from production.
It's not right, but it is a correct copy of original cross over tubes. The cross over tube has a flat indentation to accommodate the radiator stabilizing rod that goes from the lip of the cowl just above the firewall to the radiator on bottom-mount radiators. �I have never seen an original with the indentation on the top of the cross over tube where it should be. �The indentations are always a bit (quite a bit) off. �