These Chevrolet LS 821/823 Rectangular Port Cylinder Heads are a popular choice for LS engine builds, replacements and performance projects. Featuring the sought after rectangular port design, these heads are well suited to a range of Gen III and Gen IV LS applications and offer a strong foundation for street, performance and engine swap builds.
The 821 and 823 castings are high performance LS cylinder head designs, known for their larger rectangular intake ports and strong airflow potential. A great option for enthusiasts looking to upgrade, replace or complete an LS engine package.


















