Could someone tell me what i need to do to my axle to take big power.I am running full cossie running gear but am using a tuned 4.6 Rover V8.I used to work on XR 4x4's but my axle has bigger shafts and the bolts are larger and drilled and wired, could it be a 7.5" version? I already have excesive play in the diff and both inner rear shafts.Any help would be greatfully accepted.