What Is the Difference Between LS3 and L92 Heads? Choosing the Right Upgrade for Your LS Build by Chad Golen August 14, 2026 0 Key Takeaways: LS3 and L92 heads share a rectangular-port design but differ in valve specs, and spring rates, affecting rpm capability. LS3 heads offer higher factory compression and rpm stability, while L92 heads provide a cost-effective foundation for upgrades, especially with CNC porting and spring enhancements. Both head types benefit significantly from professional CNC porting … Read More