I wanna 2x @RustyNail's comment about how the 98-99 and later vehicles have all sorts of restrictions and red tape for even an engine swap that *improves* the emissions and fuel economy.
I don't remember if it was this forum or some other, but somebody documented the whole process for getting California approval for an engine swap. He owned a small livery service with a fleet of 5+ Suburbans, so he was experienced with dealing with CA DMV red tape. One '98 Suburban he bought, certainly used, was just a lemon, nothing but problems. He quickly tried to cut his losses by swapping its engine for one from a '99 he owned that had been in a mild wreck.
OMGWTFBBQ
The only good thing I will say is that the CA DMV put in a lot of work helping him comply with all the regulations and the absurd documentation and testing requirements to get this vehicle smogged and registered. He had a dedicated like "case manager" who walked him through checklists and warned him of things that can cause re-tests and delays. This inspector, and it seems the department, was on his side and wanted him to succeed and get this done.
Of course, "succeed" here means "actually survive this gantlet of Kafka-esque opaque conflicting orders without killing yourself in despair, so you can simply do business in CA". And the basic "guilty-until-proven-innocent" tone of the whole thing, the presumption everybody is either a chop-shop or just gushing toxic waste [like every single factory in China], is ugly.
The WTF moment for me was when he had to get the final emissions inspection, at a CA-certified testing place chosen by the DMV [this was some kind of Super-Smog-Check that only certain testing places can do.] He was told the name and address of the testing place ONLY THAT MORNING, and had a 4-HR WINDOW to get there for inspection. The reason for this is the state assumed that if he knew the testing place in advance, he would go there and bribe them to pass his vehicle. I assume this must be a big problem. (It turned out he failed on a single parameter but it was a faulty replacement sensor, the inspector had warned him about this so he brought a spare and personally replaced it in the parking lot (since the testing place wasn't allowed to do that work, I get that part) and passed and got his smog cert. Well, for a year at least.)
Again, this is a guy who has been talking to the DMV about this for months now, checking off boxes on forms, but the assumption is that everybody is a liar. Maybe, when government laws and rules become so burdensome that most people have to routinely cheat or work "grey" just to get by, and you have to hire more and more govt. inspectors to enforce these laws and also collect bribes to avoid these laws, and everybody thinks it is bulls**t, and all laws even for violent crime seem to be capriciously enforced and nobody cares, maybe you are in a doom loop. Just Sayin'.
I'll just leave this last thought as an "exercise for the student". You are invited to compare the concern, the govenrment oversight and regulations for:
Installing a '99 engine in a '98 vehicle
vs.
chemical and surgical sex changes for 13-yo-children