What machine are you working on? I retrofitted aux's to my BC, one of the best investments that I have made in my machine. The attachment possibilities that it opens up are fantastic. I mainly did it to add a grapple, but have since added an auger, a hydraulic rototiller, and a wood splitter to the collection. I sourced most of the parts from the dealer, it was just easier that way, and the prices were not horrible. It likely cost me about $750 by the time the smoke cleared. It took me about 8 hours to do in my shop at home. Not hard, worse part was having to pull the main control to add the third spool. The dealer was helpful, as the were able to find me an installation instruction from when there was a kit available. HTH