their all the same, 340/360, you should have a 4 digit # cast in them that is the date code like (3002) three hundreth day of 1972 so it would have been on a 73 car since the factory change over to new models started first week in August.
The casting number is 2872, which I guess means the 287th day of '72....What does the little pointer tell me?....There are the numbers 1-2-3 with the little pointer pointing to the "2".....There are also the letters "AAWJ".