N34AJ came to me with just 2 leaves in the tail wheel spring, and from all the articles I've read, it seems the caster angle was in the wrong direction. I experienced shimmy problems on hard surface landings. I had the spring re-arched and a 3rd leaf added (there was apparently a 3rd leaf at one time). After doing this, the caster angle is now in the correct direction, but I fear perhaps too much. In a taxi turn, it now wants to accelerate the turn when significant rudder is applied, causing the tail to want to swing. I suspect I need to have some of that arch taken back out to get things more civil. Right now, with an eye-ball protractor, I seem to have about 6 degrees caster angle. Any advice on what the actual angle should be? Thanx!