Sometimes it is not about an improvement.....it is just because Mopar does not have something that will work or is just flat out less money. I am planning on at the minimum a stroked 400......and I want an OD with a lock up convertor.......and the ability to have the trans shift softly when just putting yet get aggressive when the go pedal is mashed on..and have a whole different program for track day.......which leaves out pretty much anything Mopar made........and there aint no way I would have dropped 3k on a rebuilt rear end.......I have a grand total of $75 in the brand new rear housing....a Currie 9+ center case, donated from Dougs Performance Transmission in AZ and some axle tubing from Moser.......