Alot of it really comes down to the driver.
I get about 18-20 mpg around town in my '49 Panel truck, its powered by a '56 235, and has the fourspeed. I accelerate slowly. In fact, the city buses take off faster than I do. If I accelerate faster, my mileage drops off pretty quick. I also do most of my driving from 25-40 mph. I shift into fourth at about 15 mph. I'm a cheapskate, and that's why I take off and drive slow. I also live someplace I can drive everywhere on secondary roads, and not on a freeway.
I've often told friends I could retrofit their rides to get better mileage, but putting a wood block under the gas pedal, so they can't mash it down as far! No takers!
