Honestly...how good was the 318...mpg / durability / hp

I can say with confidence that the 318 in my PawPaw's 71 2 door Swinger would melt the right rear tire pretty much as long as you held the gas pedal down. It was actually difficult to take off without chirping the right rear. He did it all the time. It was a super nice car that my cousin is now letting it sit in the yard and rust slam away.