Like my Daddy used to say, when push comes to shove, you Can't Beat Cubic Inches. That said, if you you can look away from price and power, a 273 would be a beautiful thing if that was what came in the car from the plant.
Yes displacement of fuel and air (CFM), which Cid VE% Rpm all play a role NA in the amount of CFM your engine can displace, the true displacement of your engine. And CFM amount within a narrow range pretty much equals HP .