Overtime, the factory up-pipes in your LB7 Duramax can become rusted and eventually break. This typically happens where the bellows are located. Upgrade your up-pipes today with the AFE Twisted Steel Up-Pipe kit. This kit features 2" 304 stainless steel constructions with heavy duty lined bellows to ensure long term durability. The 3/8" thick laser cut flanges match the factory manifolds perfectly for a leak free seal.