Here are some pics of the upgraded arms installed. To me the replacement removes the weakest part of the rear suspension and gives a great amount of adjustment that was not available before. The arms are much beefer then the originals and the spherical end is more rigid than the rubber original. The jam nuts on both ends give full adjustability. The bolt on the left end of this pic was the hard one to get out.
The eccentric is installed as a regular bolt in this case and gives no adjustment.