Mine was doing this awhile back. It turned out that the bolts holding my carb down were loose. at high RPM's the vac. pressure kept it in place. at idle it represented a large leak, letting air in to the manifold and stalling the engine. two min. later an i was good to go
I think the lock-rite and aussie lockers should be called automatic unlockers instead of automatic lockers. they are full time lockers that automaticaly unlock when they sence a difference in torque between the two axle shafts.