Used to convert MerCruiser Marine 8.1L & 8.2L engines with thru transom exhaust to thru prop exhaust. Also requires the use of intermediate elbow kit in conjunction with this "Y" Pipe Kit. For 8.1L & 8.2L non-Emissions Control engines, use 44267A02 or 44267A03. For 8.1L Emissions Control engines, use 44267A04, 44267A05, 44267A06, 44267A07, 44267A08 For 8.2L Emissions Control engines with three catalyst exhaust manifolds, use 879288A12, 879288A13, 879288A14, 879288A15, or 879288A16. Fits all MerCruiser Marine 8.1L & 8.2L sterndrive engines, except 2012 & newer 8.2L Electronic Control engines with single catalyst exhaust manifolds.