Most builders that are incorporating our cable shifters for the "T"-type Dana 20 (with front mounted cable interface) are using 48" cables with the shifter being mounted forward of the transmission shifter. If you are mounting it by your elbow I would recommend 60" (41" working length).
Note: At this time the flush-mount shifter assemblies are our newer design that takes up less room. We will be updating the the pictures and specs this week.