FWIW, a 9" owns a rear D60.....just as strong, better clearance, lighter weight. if he upgrades to a 35-spline 9" like i said (big bearing nodular 3rd, Detroit/ARB/spool, 35-spline shafts), he can run up to 44s without any issues if he drives smart.
Not going to argue that point, and honestly, the Ford 9 inch (and to lesser extent the Ford 8.8) venture far further into the 1-ton strength range than most other 1/2 ton axles. The reason that I see more guys ditch 9" (or 8.9) in favor of a Dana 60 is because they are upgrading the front axle, and they want to keep the width and lug pattern the same.
for the front, either a D60 or, for clearance and weight, a 60-9 hybrid (9" centersection with D60 knuckles and outers.)