The length of the end link spacer should be adjusted according to your car's stance. Here's what I've been told...
You want the end link mount hole on the sway to be parallel with the ground when the full weight of the car is resting on the wheels. It's going to be different for each car. I had to cut off almost 1/2 of the end link spacer to get my sway bar adjusted correctly.
Does this explanation make sense?
If not, give Shaun a call, and he can "steer" you right (bad pun intended), and he'll probably have a good way to explain sway bar adjustments.