I just bought a 1959 PV 544 that has had an engine swap and now has a B18 in it. I don't know what version, but it does have twin SU carbs (AUD 94s) mounted on a 418404 intake manifold. The head is a 418 205 and there is a cast L 13 5 forward on the head (date code, perhaps?). The block has casting number 4968 on the left hand side followed by a 1 6 stamped on a pad and then 18489 stamped on a second pad. These are followed by a cast B18 with HBG418201 beneath it. Can anyone enlighten me as to the decoding of these? Also, where is the date code on these heads and blocks? One person told me that the 1 6 should decode to tell me whether or not it is a single or dual carb engine but I can't find any reference to that. Thanks for any help you might provide!