inspection:
it depends on the car, motor, and how much you talk.
First off, the emissions requirements are on a sliding scale. My 70 Challenger is not held to as high a standard as a 98 Lexus.
The rule is something like, its not necessarily the age of the car, its the motor inside that you are being held accountable for:
They have never opened my hood on my cars and since I failed a few emissions tests after swapping carbs, motors and other tweakings etc, I have gone through 10 or so emissions / inspections with the challenger. Never asked me any questions about it. They would have to crawl under, look at and decode the numbers on my 440 block to realize its not a 70 motor, since mine is a stock configuaration/appearance. In addition my car has the California Emissions package for 1970, but the only thing not operating on mine is the carb vapor line going to the valve cover breather. They have never looked though.
HOWEVER !
I do know a guy at work that has a '75 or so Jeep Wagoneer, that he put a crate Chevy 350 in last year. In 75, that vehicle didnt have any significant smog equipment or any catalytic converters. When he went to get Emissions tested, they dinged him for the engine swap and were holding him accountable for the year of the motor and what the restricitions would be, and so today his Wagoneer still isnt road legal because he hasnt put in the Smog equipment to go with it.
ALso my dad has a 93 Jeep XJ that is all Rock-Crawlered out, and he did talk about having to go put a new muffler on it (torn off by Rocks) before inspection, but he is in Tucson, and their visual inspection might be a bit more rigorous. No muffler is a little more obvious though, and since they have to hook up the sniffer to the exhaust your dont have to inspect real hard for that. (also have noise level laws here). His Jeep inline-6 motor puts out a stink when you drive behind it, yet he still passes the sniffer.
I think its more high profile when the motor was not an available option in that car model year that it becomes an issue (rather than a straight forward replacement motor )
It goes something like this:
If you put a 66 Olds 425 into a 82 Cutlass, the emissions requiriements are that of an 82 Cutlass
If you put a 98 Ford V6(? whatever ) into a 82 Cutlass, the emissions requiremnts are that of a 98 Ford
Here if you have a 66 or older car they dont require smog testing or yearly inspection so it would be easier to sneak a modern motor into a car like that and not have to sweat all the problems the guy with the wagoneer is going through.
I am not the AZ DEQ, so I may be slightly wrong, but generally thats the deal here as I last understood it.
