Speedmaster LS-series cylinder heads are rapidly expanding. The LS (Gen3/4) platform has many design benefits over the earlier SBC engine designs, most notably the cylinder heads. Although the GM heads are good pieces, We have developed a superior line of heads for modern performance enthusiasts. Like all Speedmaster cylinder heads, the LS-series heads are produced using our "Gravity Casting" process. This process ensures a more uniform and robust casting, laying a strong platform to build on.