ATS just rebuilt my NV5600 and installed a South Bend clutch. I was pulling a 26,000 lb load West on I80 in Iowa, going to Oregon, when a few teeth broke off 6th gear on the counter shaft (BEFORE SMARTY). With 465,000 plus miles on my truck I have no complaint. I limped on to Denver in 5th gear. I also had an Aurora 3000 turbo installed plus some gauges I needed for some time. I just wanted to say how pleased I am with the service Jason and the ATS crew gave me. They even stayed over on Friday night to get me done. The prices are not cheap, but you really do get what you pay for.