You might want to check AZ emissions laws. A friend of mine lived several years in Tucson, and the state compelled him to go out and RE install every piece of $$$$ on his old 70 3/4 T Chev p/u to pass the state smog. This included a silly spacer to connect the breather hose, which was already connected to the filter, re-finding the junk hardware for the snorkel heat, and a few other things, and bear in mind this is a 3/4 T which had no smog pump, and didn't have nearly the stringent specs for 1/2T and pass. cars.

Does your state vary from county to county?