Discussion Starter · #1 ·
So I was getting about 12.5 mpg on my '70 Chevelle SS 396/TH400 when I first got it. Had a major issue with gummed up fuel lines and tank. Replaced all the fuel lines with high quality fuel injection grade hose (in case I decide to go to FI later). Replaced the gas tank, fuel sending unit, fuel pump, fuel filter, inlet washer, and hose from carb to fuel pump. After getting everything dialed in with the idle mix screws and timing to get her running smooth my fuel mileage seems to be down to closer to 7 mpg. There are no leaks anywhere. Vacuum is good. Timing is good. What in the world am I missing here?