Interesting articles on the 273 engine

David Lee;

The main reason you do not see much about the 273 is because of the small size vs. the available larger sized engines. The 340 has 67 cubic inhes over the 273. Though it did come in that potent for of 1 bhp per cubic inch, the available ceiling of performance was greatly increased with the 340. Even the 318 has 45 cubes over the 273. That is a lot of cubes to give up.

The 273 is a great people mover engine. In order to "hop it up" some, MoPar has a book on it, the "Engines Book" for "LA" engines is a good source. The engine is limited in valve size with it's 3.63 bore. So some math is in order. For racing purposes, they suggest a notch in the cylinder sleeve itself. Keep the intake runners small instead of well ported out or 340/360 sized (Unless racing) in order to keep the engine up in torque with the high velocity intake charge. Pretty much, all other "LA" engine tricks apply and work well.