Howz this for being tardy?? I have the same fuel pump AC 40503 DZ or D2 or DU and I came up with the following: Corvette 1967 283 or 327 also '67 Camaro 396
325 HP with suffix coding MY ..
Info was taken from an old catalogue, and don't know if 'Holy Grail' but, maybe J. McN
if he sees this 'un could set ya straight..