My 427 Galaxie with a close ratio toploader , 3.89 L.S. rear runs about 3400 rpm at 65 mph . Tires are P 225 70/15 `s. 70 mph gets me up to about 3550 rpm .... and a whopping 7 mpg , which considering I`m pulling a 4100 lb car ain`t too bad ??
?? Don`t ask what happens when I bring all 8 barrels open