My '99 with Marks 4-2, 12" cans, Dyna slide springs, drilled slides, needles at 2.5, stock mains (152.5), Dyna 3000 ignition at curve #2, NGK DP8EA9 plugs gapped at .035 gets no worse than 38MPG (that's doing in the vicinity of 90~125MPH constantly) and consistently gets at least 42MPG. I've...