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I'm sure someone will have all the info. All I can tell you is that the D7T means it's a '77 "Truck" part, released for that model year (but could have had a longer run with that same prefix if no major changes were made) but the rest of the numbers are Greek to me.
Where were they? Down by the starter motor, or elsewhere?
Good luck with the decode. Do you know basically what type it is? Or are you trying to determine even that at this point?