Don, 442 did stand for 4bl, 4spd, dual exhaust for the 1964 442. It came with a 330 cid 4 bl engine, 4 speed tranny was the only one available. In 1965 it was given a 400 cid engine 3 spd or 4 spd manual trans and 2 spd automatics. Thus it is now 400, 4bl, dual exhaust. In '66 they also had a 3 two bl option so by now it was just a name. Henry.