An engine's cylinder heads and intake manifold must work together as an integrated system to produce maximum performance. The intake charge should make a seamless transition from the manifold runners to the cylinder head ports. Dart intake manifolds incorporate sophisticated wet-flow technology developed on successful oval track and drag racing engines. Dart doesn't make ''universal'' manifolds; every Dart intake is engineered for a specific cylinder head, block and carburetor combination. This means that they've optimized the port shape, the plenum volumes, and the runner angle for each application. Dart manifolds are designed to make engine building easier. For example, their small-block manifolds have provisions for ''four corner'' and center cooling. Most Dart manifolds have bosses for nitrous injectors too. Air gap under plenum and runners isolate inake charge from engine heat for a denser fuel/air mixture for more power. Single plane design for mid and top-end power. Pads specifically designed for 4150 or 4500 carburetors. Extended runner dividers equalize port lengths. Optimized runners for raised ports in 18° heads. Up to 10% more airflow than comparable models.