The first picture is the original motor out of my 66. I was getting oil in the coolant. Someone tried to sleeve that oil port for whatever reason I don't know. I can only imagine it was because of the oil getting in the coolant. The second picture is the 273 block I bought out of someone's 67. I believe the date stamp is the only way to ID the block before 68 or 69. Therefore, I am not sure if the engine I removed from the car was the original or not. The last three pictures are the replacement block I purchased cleaned up with new soft plugs, bored out and new cam bearings. Can't wait until the machine shop is done and I can get it reinstalled.