The AC number for the pump Bob is 9418. There are a couple other numbers that cross as well. One version has a glass sediment bowl (earlier model) and the newer models do not. I've actually seen (and have one) other version that works as well but don't know off the top of my head what the number is. Could check it out if you are interested. Here are the numbers I usually look for: 1523670, 1523648, 9418, 506x, 506. The first two are casting numbers .. sometimes they are listed with that only. The last two .... I think the 506x is the version with the sediment bowl and the vacumn assist. I'm not quite sure on the one that is just "506" it may be a version without vacumn assist. The standard pump number is 588 for the replacement OEM non-vacumn pump.