Has anyone actually got a Pacbrake PRXB on their PS? My truck lives at 9000', so every time it leaves the yard it faces mountain grades. I've got a fairly light Toyhauler, about 7500#, but am considering this product. It's worrisome to call over a half dozen dealer/installers, some referred by the company, and can't find but one that seems to have a clue, and prices are all over the place. I also read somewhere on this site that potential damage to the tranny and valves is possible. What about that? Seems these exhaust and engine brakes are all over Dodges, even on this site, but I would prefer hearing about experiences with 7.3s. Thanks.