Just to update here too (more on my build thread) but I've now got my own alignment kit and have set caster to 7deg.

Although I have to say - the alignment kit instructions say to do the common 20deg left, 20deg right, then double the camber measurement. But I've also read many sites say times 1.5 - and even more (reputable sites) that say use the camber difference directly with no multiplier. In the end I have to believe the alignment kit people, but it's hard to find a straight answer on caster measurement.

Why am I so suspicious? Well, I'm now at 7deg with manual steering, and although the car drives much better than the 2deg it started with, the steering is still very light. Where is this "heavy steering" I hear about?

So next, I'm in line for a bump steer kit, and I may wind even more caster on to continue my experimentation. I need to be able to trust the car the way I drive it