Mark
A spool has a lot of torque steer from the outside front tire. You load this outside front tire more by making the front stiffer. This increases the torque steer. Try less rear toe first but then try to make the front a little stiffer to add more steering traction. After this you could try the more flexible front arms.
John
Here is a more detailed post on this topic earlier in this thread.
Setting up your Roll Stiffness with a locked diff