This is the 12MM torque master kit. The 1998.5 to early 2012 24 valve Cummins engines require two different length studs. The six holes along the exhaust manifold side of the head deeper than the other twenty. The longer studs that go on the exhaust manifold side of the head are provided in this kit. If you are unsure if your 2012 engine has the longer holes or not, it is recommended that you use this kit. This kit also includes the installation instructions as well as the correct thread lubricant