Our testing has shown the stock Allison transmission is only good until ~450 rwhp. When you take in consideration the we can tune the stock Duramax engine to make ~530 rwhp that dosen't seem very fair. To give you the ability to get the most out of your Duramax, you need to upgrade your transmission, and do it the right way. Our DT750 does not cut any corners. We use the best aftermarket and stock replacement parts to ensure your truck stays on the road and out of the shop. We also give you the ability to experience the potential of your truck by adding ECM and TCM tuning at a discounted rate when you buy a transmission from us. When you spend over $4,500.00 on a performance part you should feel a difference. With the combination of our DT750 transmission, ECM tuning and TCM tuning, you will.