It has NOTHING to do with U-joint bind
If it did there could be no possible way for a coil spring car (3 link, 4 link, or even ladder bar car/truck to do it. Let alone a Top Fueler....they don't even
have u-joints. It is a direct coupler between the drive line and the pinion.......with everything solidly mounted.
Now, u-joint bind (of a leaf spring car)
may be the upper rotational limit .....but it is NOT the cause. It
may be the effect, but it is more likely that the spring tension causes the un-load. It would take very long and soft leaves to allow that much twist, hardly a pick-up truck. Lift/lowering blocks can add leverage and increase the tendancy.
But this all started about a coil sprung truck with (what 3 foot long?) control arms.......NO WAY can they allow that much rotation. It is all about loading and unloading of the suspension......The meeting of horespower and traction limits.