Ok So against the popular believe here, I have my front pinion lower by a few degrees trying to chase a caster issue myself, but mine if I have this right is 6.0* To line my driveline up like the advice here it would be about 10. It finally returns to center good, and only wanders in heavy wind like you say. I was thinking maybe my springs finally settled and my shocks too, so I was considering putting it back to 10 and seeing what I get. Then slowly dialing it back, but I really need to dedicate a day to it. My rear is 2 or 3 degrees low also because it was set with my 2" lift and my Dana 35. Now with my Ford 8.8 and a 4 inch lift I need to straighten it out too, but I have just had too many projects, and it is working pretty good now finally.
Like you I don't want to make it worse trying to make it better. Haha. I definitely want time to do it so if worse comes to worse I can put it back to where I started.