Question: Would changing the rear tyre from 285/35/19 to 275/35/19 affect the alignment? If yes, would the camber be more positive or neg?

 

Why would changing tires alter the position of the wheel?

 

The toe will be slightly negative because the tire diameter is slightly smaller by .3 inches. It won't be a major change though. Maybe about 0.05 degree change from where it's at now.camber and caster won't change.

 

How does toe change ? Camber won't change , but the front caster will.

 

I was thinking only Camber will be affected. Anyone has references?

 

unless you change offset , camber will not be affected. when just adding tire width like the OP's doing you will be adding tire to both inside and outside.