Right now I have a MK I Roadster. I live in Sacramento and frequently drive it to Los Angeles, which is around 600 miles or so. I am getting around 22mph with my 381hp 302 set up right now with a t-5 and 3:08 rear end. I can get there with about two fill-ups on the way down. I am always thinking of ways to get more power, but I really like my milage. It's not the cost of the gas, it's the range of the car. If I had a 427 I would fill up twice as much as my 302. I hear a lot of 427 owners getting 10 or 11 mpg. I'm trying to figure out the best configuration for as much horsepower and as much milage as someone can hope for for a fast street cobra that serves as secondary transportation and weekend warrior duties. If put a blower on, what would my milage be around? What about a stroker 347? If you have ok or good milage and high power readings, what is your set-up?