New bb build fuel economy

I can show you old school 383 2bbl (well I can't SHOW them to you know LOL) that banged right up against the 17-19mpg door. This would have been in a "big whale" too, but likely 2xx something rear gear.

My old 70 440-6 RR used to do 13.8,and I was not all that careful. This, at the time, was a factory stock 440-6 long block, headers, 3.54, Dana, 4 speed with G60x15 rear tires. It had a 800 dp Holley and whatever the popular 180 Edelbrock intake was. Occasionally I could get it up into 13.9-14 but that was rare, and again, I just wasn't that careful. This was before the "double nickel" speed limit by the way