Uneven Caster
 

So, ever since I installed coilovers last Fall I've noticed my caster is a bit uneven. The printout shows the left side at 5.5 and right side at 6 degrees. When I was on the stock struts the caster was pretty much dead even. The tophats and ball joints are still stock, so I can't figure out what could be causing it. The only thing I can think of is maybe the tophats not being oriented exactly the same as they were originally. Could that possibly cause the caster to be off?

It's more likely that the caster sweep wasn't done correctly before. IIRC, the stock top hats are concentric so they wont change anything if you rotate them. If you want to try to correct the caster, you can likely get enough movement from the front sub frame if you loosen it.