318 horsepower

Been wanting to do this myself. With the standard bore and a Mopar Performance 4" stroker crank, the 318 turns into a 383. Any overbore only makes it bigger. The problem is the pistons. Nobody has them as shelf stock so they are pricy. Hughes Engines has a rotating assembly for this application, but it starts at .030" overbore and 390 CI. Ain't cheap either. If you can swing the shortblock, a set of Magnum heads, M1 single plane intake(for some reason 318's love single planes) and a 750 Holley, should get you close enough to what you want that lightening the car will get the rest. You'll be amazed how much useless frippery is on a 74 Swinger. My 66 4 door only weighs 2850 lbs with half a tank of gas.