how can I determine, without knowing what it came out of, what year my replacement 4.7l is?

Did you ask the mechanic? Did you pay him? All you can do at this point is look for a serial number or other identifying marks on the engine.

yes i asked the mechanic and sometimes a sense of professional pride is just not in their DNA, so no help there, anyother way? where are any Identifying numbers

I would have said - no run, no money. Apparently they are idiots or crooks or both. I would cut my losses and find a competent mechanic. You could go to your states Consumer Protection agency as these guys should not have a license to repair cars. With the wrong engine in your Dakota it probably will never pass smog inspection making your truck worthless.

I did cut the creep, AND went to a certified shop with a good local reputation and rating ,and now, with a SECOND replacement brain, we are still stuck, he thinks maybe it,s a crossed year problem and doesnt know any more thanmyself and you scholarly gentlemen. so back to a very well broke in square ONE. ANY FRESH iDEAS YET? i PROMISE ,ANYTHING NEW i LEARN, i WILL SHARE. MOREHELPNEEDED.

Worst case would be getting a correct engine. Since you have found a good mechanic hopefully they can sort out the mistakes the other guys made. Until you identify the engine everything else is a waste of time and money. Like Jim says, Dodge is your best bet to identify the engine. Do keep in mind that it may not be smog legal so you will have to make a decision as to spending more money on a wrong engine or to buy a correct one. Good luck but this is why no one here recommends cross year engine swaps.

Maybe this article can help you sort it out ----------- https://itstillruns.com/dodge-47l-specs- 7595630.html

thank you I'll try it. I appreciate your time.