Well good idea. But think of it this way. If you put a pretty small motor in it and the car is kind of big and a bit heavy then that motor will be running hard to push that car and use more gas. Step up one more size and you will be good. That is why I think a 351 would be a better choice for that car. 302 would be ok too. I have a 302 in my truck and it get's ok gas milage but not as good as it should and I was told that I can put a 351 in it and probably get the same gas if not a bit more and more power when I want since the 302 is pushing such a big heavy truck. I am keeping my 302 though but still, just giving you an example. Good luck though, and I am sure someone here with more knowledge will chime in to help you out.