Interesting info on Arizona Emissions:
Automobiles that are less than five years old do not need to be tested.
Alternative fuel automobiles whose model years fall after 2003 do not need to be tested.
Automobiles that were made before 1967 do not need to be tested.
Vehicles that are apportioned, or licensed in more than one state, do not need to be tested.
Vehicles powered by electricity, golf carts, and those that do not displace more than 90ccs do not need to be tested.
Leased vehicles that commute into the designated areas do not need to be tested.
Wholesale dealer vehicles do not need to be tested.
It seems this emissions testing (Car Care Program) only applies to cars that either reside in the Tucson and Pheonix metro areas or commute to and from these areas. Anywhere else is exempt. I wonder how that works even with a 240Z that doesn't have a catalytic converter?
Still I don't think the emissions will be that big a deal on a 280. You best bet in my oppinion would be to yank the stock EFI harness and rewire everything with a MegaSquirt ECU and DIY Autotune Harness. Leave the cat and the EGR in place as they're just passive or vacuum operated systems. Tune the MS right and you'll never have to worry about emissions. Come to think of it, my 77 doesn't have a cat either, it's a federal model. Depending on the car you could end up without one. In Arizona there's so many nice Z cars. I've sooooo wanted to fly down to Arizona and hang with some fo the guys on here for bit while looking for another Z to drive back home.