Originally Posted by Antimullet

Shock length, unless I'm misreading your post, is a static measurement wih no load on the shock. In other words, you don't measure it with the car sitting with weight on wheels. It's not the same as setting shock preload and chassis ride height with your spring shock collars.

Reason I say this is that you mention you tried different springs to get the right shock length. That would indicate to me you were interpreting shock length as preload. I may be way off on this and I don't mean to sound like I'm stating the obvious, just thought this may help you understand better.

Also, if this helps clarify, I measure shock length always with the shocks off the car and after every rebuild or fluid change.