LS3 12-Degr Cylinder Heads Fully CNC Ported AIR FLOW RESEARCH 1845 69cc Combusti. This product data sheet is originally written in English. Cylinder Head – LS3 Mongoose – Assembled – 2.165 / 1.600 in Valves – 260 cc Intake – 69 cc Chamber – 1.270 in Springs – Aluminum – GM LS-Series – Pair. ABOUT AMCO AUTO PARTS. AMCO Auto Parts, LLC has been striving to supply and support car enthusiasts around the world with the products and service they deserve. With the economy the way it is we understand how important pricing is. Here at AMCO Auto Parts our car parts have some of the lowest prices around. With that in mind you will not lose quality. We offer auto car and truck parts from nearly 150 manufacturers. These companies are some of the most highly regarded in the automotive industry today. Our highly skilled staff is ready to answer any of your questions. We would like to thank our new and existing customers for their trust and support in our company. AMCO Auto Parts will continue to provide top notch customer service along with quality car parts and low pricing. Product images may not be vehicle specific. AMCO Auto Parts, LLC.