The carbs are known as YF as you may know already. One barrel downdraft. The "S" is Carters symbol for "assembly", I.E. not a part. Since the YF's were built between 1932 and 1962, it seems likely that the A37 and the H37 are Jan and Aug of 1937 but at the same time it's pretty incredible that you have two carbs of the same year. They are the same model and should be exactly the same. The revisions were marked "A", "B", and so on just after the "S". (964SA). Pretty sure the carbs are GM, not Chrysler or Ford.
