I had a '72 F100, also 360, 4 speed, step side, 3.50 gears , better. Put a 428 cam in it , a manifold from a '63? T-bird, Elbrock 4 barrel, headers, steel spoked wheels. The gas mileage got better at 70-75 mph! A good reason!
Run the bottom end dry one time racing a Vett. , found out later...