66 Dodge Dart GT- Deep Sixing Slant 6 and Automatic for late model 5.7 or 5.9

Me-Not being a Mopar person-what is the major difference with the newer generation of engines? I bought the Durango because it drove and the 5.9 sound good. Figuring that I could sell off what was left. Unfortunately it seems that there are more scammers and folks who want to come over and pull parts in my garage-- So, I'm going to pull the buckets out, and and drive train-call a salvage yard- or even thought of giving what left a viking send off somewhere.. Can anyone answer the question- how do I get around the ECU with all of the extras-- so much for SLT- sure a nice looking veh and fast.. Laid a 10 ft patch of black rubber out on the street-neighbor said I needed to grow up. So much for living in here in SC here in AZ. Did learn one thing yesterday about changing over motors- its a 66 and that I don't need to go through emissions- had it been a 67- then I'd have to have all of the whistle and bells....Gotta go- my kid is up and wants to be fed and to the dog park-- that's him the side bar photo...After I get the eng test stand put together I'll post some photos. It'll be next week before I can pull the eng and put it on the stand..