An implantable lead connector assembly includes contact rings, and a bulk of insulation, which includes sealing surfaces and a shank defining a distal end of the bulk. One or more conductor pins extend within the bulk and have distal ends protruding distally therefrom to be exposed alongside the shank and an inner surface of each contact ring may have a proximal end of a corresponding conductor pin coupled thereto. The sealing surfaces, in conjunction with outer contact surfaces of the contact rings, which are interspersed therebetween, define a uniform outer diameter for the connector assembly. The bulk of insulation may be formed in two parts, wherein a primary bulk is formed around a core and includes circuit-support and shank segments. A secondary bulk, which includes the aforementioned sealing surfaces, is injection molded around the primary bulk, after positioning the contact rings and corresponding conductor pins on the circuit-support segment thereof.
