Your ball joints will never make 60 additional degrees of angle, so it's a moot point, not to mention what it would do to the steering geometry.
I'm quite sure that the pre-load that the factory torsion keys apply to the torsion bars is nowhere near 60 degrees.
However, *if* the torsion keys rotated that end of the torsion bar 60 degrees when you pre-load them, then yes, rotating the keys would accomplish that.
Why bother yanking the control arms though? Just index the key an extra flat on the back side. It's just not going to happen.... Look at the difference in angle that provides 2" of lift on the re-indexed torsion keys you see all over Ebay. If that's 30 degrees off of stock, (and I doubt it is), and that gets you 2", going 60 degrees *might* get you 4", at which point, you'll have zero down-travel left in the 8" stroke on the shocks.
None of this is even taking into account the atrocious steering geometry you'd have at that point....
Not gonna happen...
-Joe
edit: Just thinking a little more.... from a strictly physical standpoint....
The position of the control arm is a function of the torque applied to it to resist the force of the front of the vehicle. To maintain the control arm in a given position, takes a certain amount of torque on the control arm. That torque is provided by the torsion bar. Regardless of where the hex is indexed, it'll take the exact same amount of torque to hold the control arm in place at that same angle. Therefore, even if you move the control arm 60 degrees, you will need to apply the same amount of torque to the other end of the control arm as if you had moved the torsion key 60 degrees. Make sense?
Many people think that the suspension is stiffer when you crank the torsion bars. That is absolutely false. The ride feels different due to the suspension geometry, but the spring stiffness is unchanged. The torsion bars have more preload on them, but the stiffness of the torsion bar has not changed.
Pretend, for a second, that you have coil springs on the front. Twisting the torsion bars is the same thing as moving the springs downward with respect to the frame. You have gained ride height, but the spring rate has not been altered. Spring rate in force per disdance has not changed. Spring position (or preload for a torsion spring) has.
Make sense?
edited again....
Think about it: What's the difference?
Let's say, for a minute, that it's possible.
Change 1: Remove the control arm, index the control arm 60 degrees on the torsion bar, then reinstall it.
Change 2: Leave the control arm where it is, but turn the torsion key adjusters such that you add 60 degrees of rotation to the back of the torsion bar.
What's the difference? In either case, the torsion bar has an additional 60 degrees of preload on it. The control arm ends up in the same place, and in either case, the suspension surely sits at the bottom of its down-travel.
-Joe