the combo you are using is perfectly ok, and you can expect no problems to arise. what the benefit of changing to the later model pump parts is when you are shopping for, or need a converter that is, or has very different characteristics than your stock 1965 converter. the early [65 & earlier] converters are hard to find and much more expensive in a performance, high stall speed, design than the later converters are, hence the pump changes to take advantage of the vastly different, superior, and much cheaper converter offerings. hope this clears up the understanding of the reason to swap to later parts.