So. the standard 210mm diff from a e320 will handle the torque. If you want the v8 subframe it has a better rear mount for the differential but the diffs are the same size. Just a different rear cover for the subframe. The axles will handle street tires just fine and until you are trying for sub 1.7-1.6 60' in the 1.4 mile you are fine. As far as the driveshaft just get a custom one made it is cheaper and better than buying a factory driveshaft and having it modified. You eliminate the flex discs and put an aluminum adapter to a 1340 u-joint. Axles there are really no upgrades unless you really get into the custome world. I have a thread on some of this stuff here. I am doing a 215mm diff with a lot of factory parts but also a lot of custom machining and a widened track to accommodate the axles. But I am going to launch hard at the drag strip.