top diffs mines been fine now with 500bhp and the same ish torque for 3 years but when its apart shot peen and super finish your cwp i dident and lernt the hard way ripping all the teeth off mine lol and i payed 700 pounds for mine then about 60 pounds for all the bearings and seals also a few quid for the crush washer a new pinion nut so cheap too but i did have to mod the diff case as they are hard to get in!