Denny, about 10 years ago Mopar Muscle magazine ran an article on the subject of porting heads. In the article the benefit of each porting procedure was individually evaluated on the dyno. The low hanging fruit was in the bowls below the valves where there were sharp angles at the interface between the ground valve seats and the casting and around the valve guides where they protrude into the ports. Blending those areas created the biggest improvement per hour spent with the grinder.
I have a set of Edelbrock "Performer" heads on a SBC powered street rod. Those heads have small ports for good velocity at low RPM but the bowl and valve guide areas have no edges or bumps that would create turbulence. Those heads are probably a good example of what a street port or manifold should look like inside, small but with nothing sticking out into the air flow.
Even an ancient stovebolt engine can probably benefit from optimized airflow, distributor mechanical and centrifugal advance curves and carb. jetting and the result will be improved throttle response and economy.
The 360 CID Mopar engine in my '71 Dodge van runs better in all respects, including fuel economy, with a Comp Cams very mild camshaft, bowl ported heads, recurved distributor, small port intake manifold and optimized jetting than it did bone stock. The same result would probably be obtained with any Chevy or GMC engine.
