Ask Chip about HEI units in 235's. He could write book... :rolleyes: well, I guess he already has.
The problem with judging your truck's performance by m.p.g. is just that... miles per gallon of fuel burnt. My Zenith single-barrel is about as "adjustable" as garden hose, and I need to pull hills with a load; I can't change the fuel mix or timing too much. Until you get some longer legs under it, it will always be slow and thirsty. I had Randy's R&P shove 4.10's in it and without even adjusting the carb I'm well into double digits.