Externally adjustable extrusion insert for a multiple-orifice extrusion manifold. Adjustments to an extrusion insert precisely controls the extrusion path leading to one or more extrusion orifices of the manifold. Each insert is adjusted to reduce or eliminate variations in extrudate exit velocity among orifices in the extrusion manifold. Precisely tuned inserts provide extruded products of uniform length. Choke plates controlling the flow of extrudate to each orifice. Choke plates are manipulated with an externally adjustable cam. Such adjustment compensates for variations in temperature, pressure, surface properties, geometric variations, and other conditions which may affect extrudate flow rates through the orifices and extrusion manifold.