I ran a 27 spline 8.25 on 33" Swampers and it never broke. The only time I was easy on it was while on the road, although I did do burnouts & donuts in the XJ from time to time on the wet pavement. Oh, it was welded, too, and I never had the first problem out of it. The guy that bought it from me is still running it (on 35's now, IIRC) and it's still going strong. And yes, it went through Tellico, as well as Beasley Knob, Uwharrie, etc.
I'm not saying that the arguments here are not valid for the use of Dana 60's and whatnot, but the simple fact of the matter is that the 8.25" rear (in either form-27 or 29 spline) is a very stout axle if someone without fab skills is looking for a serious upgrade over a Dana 35.