On Hamtramck E body vehicles I'm curious to know if the left valve cover should have a 3 digit bin code towards the front of it as typically found on "B" & "RB" engines. If so, what are some of the more common numbers floating around out there for 70-71 340's ? I'm sure there are quite a few variables regarding this subject not only from plant to plant, including but not limited to shift, gate, which line, etc., etc. Thanks regarding, Tommy