Your cummins a auto or stick? I had a 2000 3/4 Dodge with the 5.9 and NV4500 transmission. I had a set of 100HP bully dog injectors and a TST comp box on it. Still useing the factory turbo, my truck made enough power to break the transmission. I could smoke the tires in 3rd gear towing my race car. I was pulling back on to the highway after stopping. Had the trailer and car in tow. A car was coming aot faster than I thought so I had to get on it hard to speed up. Needless to say I ripped 4 teeth of the 3rd gear on the counter shaft..after that I turned down the comp box while towing. Lol