has an article about a 71 Challenger Sixpack car. According to the article, the owner had his carbs re-built, replaced the stock bases with Pro Max units, tuned up his 440, and is now getting 18 mpg on the highway. How the heck is he doing that? I'm lucky to get 8 or 9 mpg with my Sixpack. Also, what the heck is a Pro Max base and what's the advantage of installing it? With the huge gas prices these days, and how thirsty my car is, I'd sure be interested in upping my mpg's.