Hey all, I just installed a fresh 400 rebuild in my truck, same motorcraft 2v carb and manifold, stock rebuild except for timing chain and cam. My mpg right now is around5-6 intown, I know motors are tight when they are fresh but this seems really low. Before the rebuild I could count on around ten in town and 14 Hwy, maybe I will gain 1-3 mpg's after breakin. But this is worrying me.
What are you people getting for mpg with your 400's?
In My Pull Truck I run Low Range 2nd Gear during a pull.Most pulls are 300 feet long. I usally end up in the 285 to 295 foot range.
I burn 3 Gals of Phillups B 33 racing fuel at $9.50 a Gal. per pull, And I pull in two classes at each event .
So every two runs it cost me about $57.00 .... How far can you go for $57.00 in your Truck.
Well I have a '78 currently with a 351M c6 tranny, 33" tires, 3.50:1 rear end and around town I get about 8-9mpg. Its a stock rebuild except I added edelbrock aluminum intake, holley truck avenger carb (670cfm), free flowing dual 2.5" exhaust with dynomax headers. But I am still tunning in my carb and timming. Its been an ongoing tunning adventure lol!