I agree with Greg my 218 has had the head shaved and is now about 8 to 1 c/r. I have a fenton intake, dual B&B's, headers and dual exhaust. First and second gear are a little livelier but from 40 to about 65 mph there is a huge difference. I didn't notice any major difference in fuel mileage, I get about 21 mpg at 60 mph in overdrive. You can sinc the carbs with a length of heater hose and a good ear if you don't have the proper tool. I plan to pull the engine this winter for a freshen up and will install a performance cam at the same time.