Small block mileage

What's good mileage .. ?? I'm asking because of all the older small blocks I've owned, the 318 has been probably more efficient than the other brands. Like 289's, 302's, 283's... I've owned and driven them all.

• 318 2bbls on the highway have got 24-25 mpg easily in the 3-OD cars, and most can get 21-22 otherwise in smaller cars.
• The difference between 318's and 360's?? In heavier vehicles or bulldog nose vehicles, sometimes the 360 actually can do better.
• We've taken a C-body on vacation with a 360 and averaged about 17 mpg rollin' 65-70 mph.
• Our '77 full time 4x4 Ramcharger got 13.5 mpg on our 4k mile vacation cruis'n 60. Our '77 Short Van B100 with the 318 2bbl average the exact same. We hoped we changed that with our mods to the van, we'll see.