Making Power 318

First thing to is what Rusty said. Make sure it is healthy with compression check etc. Next crawl under and see if the rear axle has the ratio tag on it. If not spin the wheel and count the yoke revolutions (lots of youtube videos on figuring out axle ratio). There is a good chance that has a 2.76 or higher gear (I know someone with that has a 8.25" axel and around a 2.46 ratio!) They were looking for low RPMs for fuel mileage back then. If you have one of these tall gear it will feel like a dog if you are expecting it to run like a hot rod!