318 fuel mileage

Thanks again all for the info, from what I have gathered here is that if I do a good overhaul on the old electical systems and tune everything to spec and maybe some nice exhaust and a manifold it really shouldnt do to bad unless my foot gets heavy. I just realy miss the on demand power of my V8 compared to the slant.
Now an age old question, if you are keeping your foot light can a four barrel get better mpg than a two barrel? as the primaries are smaller than that of a two barrel and it only really sucks fuel when you open up all four? Or is it just a myth?