I have the 29 spline 8.25 in my 97 with a detroit locker and 4.56 gears. It has not had ANY issues yet in the last 6 months since the chage to 35's. It has Yukon Shafts, but I've heard the stocks are almost as good, so I wouldn't sweat it.
As for the front...I also have the D30 with a trutrac. I have snapped one axle at Johnson Valley, but the consensus was that it was a bad axle from the begginning. It was a Yukon 4340 and was only a couple months old. I was only running 33's at that time. I have had no problems with them since the 35's. If you wheel very hard...especially rocks...then I would suggest you upgrade your front axles.
4.56 is the lowest gears you can get for the 8.25. I would like to have 5.13's myself, but it is mostly a trail rig...no normal driving duties.
The only "problem" I have with this set up is the brakes...they could be better, but they do stop me fine.
