[HO455]

The OP hinted that the engine was be rebuilt. If so then a thorough blueprinting of the assembled components will be beneficial. A thoughtful selection of parts (Like modern low tension piston rings) with the intent of maximizing engine efficiency at low RPMS will pay for itself in the long run.

We must also accept the fact that cylinder head technology installed on our trucks was not very efficient even back in the day. That being accepted then it makes sense to go to a more modern cylinder head. Vortex heads or one of the numerous aftermarket heads will have more efficient combustion.

Modifications that improve movement of air into and out of the cylinder head will help as long as port velocities are maintained in the target RPM range. The Vortex heads were engineered with this in mind. They were never expected to be a high RPM performance cylinder head.

Having a properly curved distributor with a blueprinted vacuum advance helps ensures you don't waste any fuel due to late combustion events.

Then let's not forget physics. It takes 14 parts of air to one part fuel (For arguments sake.) to have good combustion. Going to a smaller cubic inch engine will help reduce fuel consumption as long as the engine isn't asked to run too hard.

And while on the subject of physics driving at 55 instead of 60 saves fuel as the power required to push an object through the atmosphere increases exponentially as speed increases.

Thanks for startng this great thread.