A professionally prepared Dana 60 with chrome moly axle tubes will not be that much heavier than a comparable 9 inch(unless you use the aluminum center section on the 9 inch) and the Dana 60 does not have the frictional losses that the 9 inch has As far as gear changes for the 1/8 versus the 1/4 not many racers change the grear ratio that know of, just spray a little more on the line or ten feet out