i think they are defo shorter, by 4-5 ml. I took the old arms out, put them either side of a new one, put a bolt through where the pivot bolt goes and a metal rule across the base of the ball joints and there is a gap between the new arm ball joint and the rule.

but when using the wheel alignment equipment at work i found that the new arms must be shorter as it improved the camber of the wheels and moved it from a negative camber to bang on to manufactures spec.
Whooty