I have a Pacbrake on my truck. I bought it over the internet, not sure anymore what company. I would just do a search for Dodge exhaust brakes and do some research. I don't think it really matters what brand, but I've never had any major problems with mine in the 6+ years I've owned it. Your friend will probably have to have heavier valve springs with the brake; I'm not sure as to the technical reasons. Maybe someone will post that knows more than me.