I have the earlier distributor which is dated 519. My car's SPD is Feb 10, 1970. I think you would be fine using that one for your car if you could locate one. I would think that the factory would use up the earlier distributors first, before changing to the others. Since the one I have was dated the second last week of 1969, that would indicate to me that if that Jan 1970 date was an absolute cut off date, the earlier Prestolite ones would have ceased production much earlier than the end of 1969. Am I making sense?