Abstract: An intake manifold is formed by two half-shells into which inserts are mounted to form intake ducts. To adapt the manifold to internal combustion engines of differing displacements and to achieve sealing of the intake ducts relative to an air-collecting region, the inserts are inserted into a half-shell with an overlap between adjacent parallel wall sections and the extent of the overlap is selected according to the desired cross-sectional area of the ducts. Sealing of the intake ducts is accomplished by providing seals along flanges which are spaced from the intake duct by a distance corresponding to the overlap of the parallel wall sections.