Read the other posts and what most people are saying is right i think mate. its the camber due to lowering. if you replace tyres b4 sorting this you will eat them again. had two saff cos replicas based on 2.0 pinto engined sierra and they were both lowered and both ate the inner edge of tyres. so far as im aware its recommended that you dont go lower than 25mm with a saff. hope you get sorted buddy