Part of "this stuff" is why I settled on a 67. (Pre smog). At the time I was looking, Spokamentro (WA STATE) was causing smog problems in IDAHO. The EPA of course has a monitoring station, and there were people "making noise" about passing and reuiring smog inspections here in N Idaho. (There are two counties, I think, in S Idaho that require inspections)
At the time I did not know that AZ requires inspections on 67 cars, which should by default be outlawed. THERE WAS NO smog specifications for 67 emissions other than CA state, and federal cars were exempt