This kit seems to include most everything you'd need to install a 392 EC HEMI engine into a vehicle, from essential components like the catalytic converters, O2 sensors, and PCM to smaller details like nuts and studs. The inclusion of an instruction sheet is particularly helpful for ensuring a smooth installation process. And with CARB E.O. D-265-62 certification, it complys with California Air Resources Board regulations, which is great for those concerned about emissions standards. Overall, it is a well-rounded package for upgrading or replacing an engine.