Sierra 18-1233 Timing Cover Seal for 7.4L GM EnginesSierra replacement timing cover seal. Sierra aftermarket parts are manufactured to meet or exceed OEM requirements.Fits 7.4L/454 CIDInterchangeable with: Mallory; 9-61612; Mercruiser Stern Drive; 26-49154; 26-821947; 26-8219471; FI1100986; OMC Inboard; 3860095; OMC Stern Drive; 3860095;