Need A Recipe For A 273 Rebuild

It's true, to get the most out of a 273, it likely wouldn't be very streetable.
Still, the potential is there for a good street engine. 300hp is nothing to sneeze at, especially in an a-body. That's a low 13 second car!

The problem is the bore size, it's very small. You just can't really pack enough in there to make huge power.

They can be made to run though. As an example, there's a '65 Valiant with a 273 in NHRA stock (in the Pac. NW div.) that's run at least an 11.75. Pretty stout if you ask me. But then again, it's stock eliminator, so they have a lot of duration on the cam, high stall converter, steep gears and don't really get going until the upper limits of the rpm range. Again, probably not what you're looking to do, but clearly there's a way to get power out of these engines.

If you're only looking to get 275-300hp out of it, you should be good to go.

See this link for a page about the Commando engines:

http://users.erols.com/dmapes/THIRD.HTM