273 Commando Engine Clone

You can probably get a 2bbl piston cam today that will give you the 235HP of the 4bbl, don't know about the torque. You can build a 318 with the 273-4's torque and the HP and dress it with all the 273 bling.. grind the 318 casting off the side...only you will know the CID.
Did the 273 not have casting numbers ? My father has a few 318 blocks laying around his shop.