I have never had a vehicle that only got 7 mpg.... my dually got 10 and that was my worst ever..... that was a 2 bbl 360, 4.10 gears, granny low 1st gear 4 speed stick.... in a HEAVY truck. My 79 D100 shortbed, with a slant, and 3 speed manual, got like 18 in town and 22 on a solid highway cruise back when I had it a lot more weight there than your Dart. something is definitely WRONG there...… Ive had a few slants over the years, as have my son, Dad, and brothers..... none were that bad//// surprised your engine isn't hydrolocking with that much gas going thru it....
the slant was always the "economy" choice..... a HP fire breathing 340 in an A body would be more efficient than what you are claiming.
