7. While you can get a Pro or ProRock 80 built with 35-spline shafts (middle), why would you? For something with small tires that never gets locked into low range it might be ok, but we needed bigger. Shown on the right is our 1.705-inch-diameter, 40-spline axleshaft. To the left is a 1.31-inch-diameter, 30-spline Dana 44 shaft for comparison. Our massive shafts are plugged into an ARB Air Locker for the best on- and off-road performance. Again, Dynatrac uses only shafts made right here in the USA.