The failure is so much worse than the lifters. There is a systemic failure at GM right now where they are ignoring these problems, and have been, since the AFM/DOD system first debuted in 2007.

B e careful when purchasing new plastic lifter guides for GM’s LS engines. It’s always a smart practice to replace the lifter guides when rebuilding an older LS engine as the material can ...

The AT4 will be the highest-riding Sierra, with 2 inches of additional lift thanks to lifted coil suspension and new 35-inch tires. AT4 models will also share a number of features with GMC’s ...