Abstract: A convertible intake manifold for a V-block engine has a base member and an interchangeable center runner member isolated therefrom. The base member has a coolant crossover section at one end; a distributor boss section at a second end opposite the one end; an engine valley cover section between the coolant crossover section and the distributor boss section; and a pair of port sealing sections, one on either side of the engine valley cover section between the coolant crossover section and the distributor boss section. The port sealing sections have a thickness equal to or less than the thickness of the remaining base member sections for allowing maximum flexibility in selecting a runner configuration for the center runner member. The center runner member may have any runner configuration with runner mating faces configured to be interchangeably attached to the V-block engine without removing the base member.