I think the answer to Mr. Znut73's question would be that

the smog equipment would needs to be carefully removed a piece or two at a time. Some pieces are interconnected, so you'd probably want to remove them all at once. The tricky part is to re-tune the engine each time to get it working well without the emmissions parts. Just taking the emmissions parts off will totally throw it off for both power & fuel efficiency. that is why those pumps and hoses were added- to increase the eficiency. So if the emmissions parts are still working well, there's no need to take them off.

With the way the value goes with the early cars, those without the smog equipment has much less value, so you have two reasons to keep it on and working.

Move to Nebraska and put a massive smog producing V8 in that baby!!!