Questions about 1303vw73s ride

[1303vw73]

When you say lower the car one spline, do you mean just move the spring plate one outer spline, or move the inner end of the torsion bar one spline also, like the Bently manual describes? How much will one spline lower the rear end? Will the negative camber have any major effect on the wear of the tires? Thanks guys for all of the information.
Kyle