What an education! Thank you for all your hard work researching this.
I have a 1982 Buick Regal Limited 4 door with 83K miles on it. Literally driven by an old man and his wife locally and does not have a dent on it. I am going to turn it into a sleeper. I live a few miles from dismantlers heaven, Pick-Your-Part. I have seen many 3.8 Turbos in Regals, GN's, Monte Carlo's etc.
Well... sleeper and camping trailer tow vehicle lol. This crash course you laid out here is fantastic. This is going to be a fun project for sure