318 MAX fuel economy builds?

Dmopower said
The 920 273 heads have small ports and require porting and larger valves to get it to flow close to std J heads. Which is my goal to get them as close to J heads or better at .450" .5 lift. These smaller ports should help velocity and efficiency if I follow all of the good advice and pics this site has on the subject. But I'd be open to hiring it done. I know there are guys here that are far more skilled than I. I have a set of 920's on my 273 that I ported and they are working great. Just a mild bowl port and gasket match.

Just spitballing not saying your wrong and or not partly true, but the main goal is to make the part throttle hp needed with less fuel and air, so less friction, less pumping loss so less restrictions from air inlet to exhaust tip, more cr, more efficient combustion, less heat waste, lighter rotational parts etc... Plus need less hp in the first place with less weight and aerodynamics.

Don't know if velocity gonna help much, the engine gonna have zero problem with the air requirements for the little hp needed, plus by time your done porting will there be that much difference between 920 and J heads? Heads are the number one way to make power look at LS and modern Hemis massive port flow small cam, cam choice can be one of the bigger mileage killers I'd still run better heads even if it cost slightly to mileage which I doubt would be noticeable and probably would be better cause you could run less cam for same or more hp.