California was the center of hotrodding activity long before CARB came along...a lil bit of government restriction isn't going to shut down an entire industry.

Pretty much every state aside from NY and CA has very lenient emissions laws. As long as you've got a cat bolted up you can pass. I know in Maryland they put you on a dyno but the actual numbers they have set as standards are pretty easy to pass.

I just go to school here in Wisconsin so I don't know what the deal with smogging a car here is but I would assume that it's similarly not much of an issue.

If you want to pass smog in Cali the best option is to get a USDM motor of the same model year or newer than your car.