A 302 will use more gas than a modern fuel injected engine. A 302 could have come with a 3 bolt Holley or a 4 bolt Stromberg. They are both good carburetors and a carburetor is a carburetor. They use gas to produce horsepower. Going to a 3.55 rear will help some. Keeping your foot out of the carb will help a lot, but that takes the fun out of it.
