Small block mileage

Had a slant/904 2.76 in my 68 dart more door. Usually got 16 or17 mpg jamming at 75 mph. Went to 318/a500 and 3.23 gears usually got 20. Car was 10x more fun to drive too. My 95 ram 1500 4x4 with the 360/518 and 3.5 gear gets 18 empty and under 65mph, 11 flogging it loaded heavy.

just too many variables to say any engine is a “gas hog” and another isn’t. A 500 inch 440 in something light and pointy could get better mpg than a slant in a d500 dump truck