How do I get more performance and better fuel economy from my 78 Vette?

If you're worried about fuel economy, you've got the wrong car. Seriously, do you really put that many miles on it that fuel economy is an issue? As far as power, Chevy engines are easy to modify. Start with headers, intake manifold, camshaft, and carburetor. But, keep the original parts, if you have them, to re-install when you sell the car. Modifications like that decrease the value of the car.

I asked a what I thought was a legitimate question, I was not looking for a snide answer. I have owned several Corvettes and NONE of them got 12 MPG like this one does. Perhaps I came to the wrong forum to get meaningful input. Sorry I wasted your (and my time).