Why a front locker?

Much easier to snap with a locker. I'd bet a locked rear would take care of most things (typically at least one rear wheel is on the ground when rock crawling). Maybe a truetrac or similar clutchless LSD is as far as I'd go in the front.

Also, if you're overheating the brakes due to Atrac, it's probably time to reconsider your approach (angle, speed, whatever).

 

I probably mentioned it earlier on this thread, so sorry to repeat - somebody posted a YouTube compilation of eight or ten CV axles snapping. That made me leery of pushing the envelope with a front locker.

 

I recently regeared to 4.88 Yukons and kept stock tire size with Bilstein 6112 and 5160 shocks. Puliing a 2000 lb camper trailer in the mountains of Arizona is now much more fun.