My '62 gets 17mpg with a 3.23 Dana rear end, tall tires, 4spd OD manual trans from a '81-'87 Chevy, 290hp crate 350, old Edelbrock C3B intake and 600cfm 4bbl carb.
The overdrive is .72:1. I would get a lot better mileage if I didn't honk down the highway at 80-85mph, but I can't help myself. Normal cruising speed is 75, in the left lane. I drive it like I would any other vehicle.
My 2001 Dakota got the same mileage, driven the same way.
I think a more modern intake, more free-flowing exhaust manifolds (2.5 inch Rams Horns in place of the small 2-inch on it now), and some other improvements would bump that up a bit.
I also have a clutch fan on it, which helps.
I'm also certain either a 2bbl carb or a Quadrajet would help things too... though really, keeping my foot out of it would be a the first huge step!
-Brad
