New GM LSA CNC Ported Cylinder Heads - Set (12675872)

Brand New. Ready to Bolt On The ultimate upgrade for your GM LSA engine - our brand new LSA (GM part: 12675872) XtremeCFM CNC ported cylinder heads. CNC Ported, Decked and Ready-to-Go These stock LSA heads have been taken to the next level with our 5-axis CNC porting program, strategically removing material from the intake and exhaust ports and contouring them for maximum airflow. The stock LSA/LS9 cylinder head and engine combo yields a 9.1:1 compression ratio. After porting we deck the head 0.026" yielding a 9.38:1 compression ratio (when using the stock engine configuration). The stock springs are replaced by BTR 0.660" lift dual springs with titanium retainers for your larger-than-stock camshaft application. No Cores, No Fuss Note: We don't require any return core. These are brand new heads and if they are listed as IN STOCK they will ship within 24 hours. Again, these heads are brand new (never used) and are run through our standard LSA head porting procedure which includes: Disa