I'd certainly invest in ground clearance before a driven front axle. Beyond that, there's a lot to be gained by scouting tricky sections and then taking them with some momentum. I don't have experience with lockers, but an lsd goes a long way in terms of not having to back up and re-try. I'd bet a locker would go even further.
Originally Posted by Karsten
I've taken my 2WD with LSD in the rear to places where it doesn't really belong. I prefer a LSD/TrueTrac style over a 100% locker on the street, especially on snow or ice.
The LSD/TrueTrac style always gives you more traction than the open diff. On snow/ice you have either 0 or 100% with an ARB.
On snow/ice you want a modern awd system with sensors and traction control. I was lucky and ended up with a decent one in '02, but most of the others have caught up by now. A locked center with open diffs on the axles is better than 2wd and nothing, but not much. Adding an LSD just means you're less likely to get stuck, but will be sliding (just a little) through almost every turn. It's manageable, and works, but it's nothing compared to modern traction control.