An injection molding process for making a plastic article, the process comprising the steps of: A. Forming a moisture-curable composition comprising a 1. Silane-functionalized polyethylene, 2. Moisture source, e.g., a moisture-containing filler, wherein the moisture source excludes alcohols, and 3. Condensation catalyst; B. Injecting the composition into a mold; C. Subjecting the composition to conditions sufficient to 1. Release moisture from the moisture source, and 2. Partially cure the composition; D. Removing the partially cured composition from the mold; and E. Continuing the cure of the composition outside of the mold. The process is particularly well suited for the manufacture of thick parts, such as wire and cable elastomeric connectors.