21 mpg?!?
tunnel rammed 340 dart gets 14mpg combined -and thats with a little punishment here and there,3.23 gears,904,2500 stall.if you drive it with a light foot it gets around 16mpg maybe better if you drive the speed limit on the highway.i had a 73 valiant with a warmed up 318/904 combo with 2.76 gears isky rv cam,4bbl,dual exhaust.it got around 20mpg on the highway.wife 66 valiant slant six 2bbl gets about 18 combined city/highway.