Mishimoto 01-05 Chevrolet/GMC 6.6L Duramax (LB7/LLY) Transmission Cooler Line KitEvery truck owner knows that it doesn't matter how powerful or reliable your engine is if you can't get any power to the wheels. The transmission mated to your 2001 2005 LB7 LLY Duramax is essential to everything your truck does, and keeping it cool is crucial. Upgrading your transmission cooler with a Mishimoto performance transmission cooler is a good start, but the fluid still needs to get to the cooler. That's where this 2001 2005 GM 6. 6L Duramax