eight Bosch-type, top-fed, electronically actuated fuel injectors; there was one injector located in each intake runner. Each cylinder had its own injector, thus making the fuel system a "multi-point" type. Fuel pressure was regulated by a vacuum-controlled pressure regulator, located on the return side of the second fuel rail. Excess fuel was thereafter delivered back to the fuel tank. (Later versions had the regulator and filter mounted at the in-tank pump). To support the new fuel system, the intake manifold was of a new design. Known colloquially as the "beer keg" or "kegger" manifold, the part was shaped like half of a beer barrel lying longitudinally atop the center of the V-shaped engine block. The intake runners, which supplied the fuel and air to each cylinder, fed each of the intake ports in the newly designed cylinder heads. The bolts that secured the intake manifold to the cylinder heads were installed at a different angle from those on the older LA engine; they threaded in vertically, rather than at the 45-degree angle of the 1966-up LA. Air was provided from the air filter intake to the intake manifold by a Holley-designed, aluminum, twin-venturi, mechanically actuated throttle body, which was bolted atop the intake manifold. Each venturi was progressively bored and had a diameter of 50mm. To this unit were mounted the Throttle Position Sensor (TPS), Manifold Absolute Pressure (MAP) sensor and Idle Air Control (IAC) valve (initially referred to as the "AIS Motor"). A steel cable connected the accelerator pedal inside the vehicle to a mechanical linkage at the side of the throttle body, which acted to open the air intake butterfly valves inside the venturis. During idle these butterfly valves were closed, so a bypass port and the IAC valve were used to control the intake of air. The cylinder heads were another fundamental change of the Magnum engine, being designed to meet stricter requirements in both power and emissions by increasing efficiency. These heads were cast iron units with new wedge-shaped combustion chambers and high-swirl valve shrouding. Combustion chamber design was most important in these new heads: LA engine cylinder heads were given a full-relief open-chamber design, but the Magnum was engineered with a double-quench closed-chamber type. The higher-flowing intake ports stepped up intake flow dramatically in comparison to the original LA heads, and the exhaust ports improved cylinder evacuation as well. The shape and porting of the