The Stovebolt Site Forums The Shop Area General Truck Talk 7.8 miles/gallon, sound right?

Somewhere along the line I'll have to address my speedometer issue. Then I'll be in a position to look at my fuel mileage with some degree of accuracy, but this I CAN tell you right now: Auld girl is going maybe twice as far on a gallon as when I first got her to run reliably. The radials (31" tread height) and the 4.10 diff have made a world of difference. Denny, you need to troll the wrecking yards for 8-hole Suburbans and automatic tranny trucks between '67 and '72. That's where your 4.10 will most likely be hiding, and when it has been installed, you'll find yourself happy at 50-60 mph. When I had the original 5.14 ratio I was always in top gear and always winding fast except when the traffic lights were close together. In fact, the ONLY time that truck was happy was when she was loaded to the gunnels. Now I can run all day comfortably, loaded or empty and, while I don't know what the number is, fuel economy - while not great - is acceptable.