CNC Ported Stage III GM LS3 Cylinder Heads

PRICES ARE PER PAIR - NO CORE CHARGE These seasoned GM LS3 heads have finally been given a chance to breathe after a full treatment on our state-of-the-art CNC equipment. That includes porting on our 5-axis, a CNC valve job on our Newen Contour and getting milled to perfect flatness on our Berco (see videos down below).The port work brings the intake runner volume from 257 to 284cc. The exhaust is increased from 87 to 99cc. Take a close look at the spin video and photos showing unsurpassed quality of the machining work.  As seen in the chart below, our CNC porting has the most pronounced effect on exhaust side airflow.   We assemble these heads using GM valves, and beehive springs .625" Max Lift, Coil Bind @ 1.060".  Other valve and spring packages are available. Unlike pure head porters, we build engines. While flow numbers are useful information,  we really like to see how they do on our dyno. Better yet, we want to see how they do on the track. Furthermore, we intentiona