Technical Establishing wheelbase question...

When setting the wheelbase, can it be done with the weight off the suspension or does it have to be done at approximate ride height? Just wondering.

 

That depends on weather your working with a Buggy Spring or leaf spring system.
The Wizzard

 

And actually wheelbase has nothing to do with the springs if your running Fenders. Wheels need to be centered in the wheel opening and build spring mounts accordingly.