Hi, The 320 road master is longer than the 263. I have a 263 I plan to put in a 37 chevy pickup. The auto engines had diffrent crank shafts than the standard transmission engines.If you want to use a standard transmission you might keep this in mind. I plan on useing a T5. My brother knows all about these engines. He is the one that wone the championship with his buick stright eight.
