[IndyCobra]

That's a good question and I'd be interested in the answer from the professionals. It's hard to explain, but I adjusted mine so that when the hydraulic cylinder is half-way through it's arc, the clutch fork is parallel with the ball. That way, it swings the same distance forward as back.

I'm not sure it really matters. It can be adjusted to just about any point by changing up the height of the pivot ball or adjusting the spacers where the hydraulic cylinder connects to the clutch fork.