Anyone install Edlebrock aluminum heads ?

6mpg most likely means the guy can't tune his engine. ;)
Taking heads off a running engine just to mill them mostly turns into a full/partial rebuild because you will always notice things you can't leave 'unfixed'.
A cold air-intake system could also bring back some 'peppyness' to an engine.
Maybe your right. All I know, he started it in his garage under his house for me. Yep, sounded like 6mpg, lol ! Incredible sound from a small block. I didn’t have to drive it or ride in it. You could feel the power at idle standing beside it. He races it. But, has a throttle valve on the dash that would tame the power to make it street friendly. Extremely nice car and set up. I’d like the same. But, if I were to spend that kind of money. I’d prefer to install a big block to increase my car’s value and it would be about the same in price. I’m happy with what I have because I don’t intend to sell it. It’s a very good running car.