Sierra 18-2743 Mercruiser Outdrive Housing GasketSierra high-quality engine parts are designed to meet OEM specifications. Fits R, MR, Alpha One & Gen II drives (s/n 6225577 & up) (1983 & up); Interchangeable with: GLM; 31141; Mallory; 9-61012; Mercruiser Stern Drive; 27-94996A20; 27-94996; 27-94996A1; 27-64818A2; 27-949962; 27-64818A3; 27-94996A2; 27-94996Q2; Application:Mercruiser Stern Drive Alpha One Gen II; 1998-2013; s/n 0L100040 & up; Alpha One Gen II; 1996-1997; s/n 0F680000 thru 0K999999; Alpha One Gen II; 1991-1995; s/n 0D469859 thru 0F679999; R/MR/Alpha One (Sterndrive); 1983-1990; s/n 6225577 thru 0D469858; R/MR/Alpha One (Transom Assembly); 1983-1990; s/n 6216687 thru 0D469858;