4 Speed Id

Hey all I just picked up a 4 speed and was hoping some one could id it. I have done some research and didnt turn up much. It looks to me like it maybe from an A/F body car. I know its 68 or newer from the pad on the side. Case is all cast iron, it has only one mounting spot for a shifter and its at the back of the tail shaft. The numbers on the pad are as follows 6B1 0552 the next set of numbers PP833 5206. Any help would be great Thanks Ken