What is the gas mileage of a 1972 Chevy pickup?

Many variables here, 6 cylinder, 8 cylinder small block, 8 cylinder big block, 2 barrel carburator, 4 barrel carburator, automatic transmission, 3 speed standard transmission, 4 speed standard transmission, 2 wheel drive, 4 wheel drive, 1/2 ton truck, 3/4 ton truck, 1 ton truck, lwb, swb and the list goes on.