This product has been discontinued by the manufacturer and has been superseded by Sierra 18-5273CDI E66-0012 Tune Up Kit The CDI E66-0012 Tune Up Kit is designed for use with Mercruiser engines with Thunerbolt IV & V HEI Ignition. Fits: Mercruiser 1983-1984 198, 898, 5.0L GM (305cid) 1985-1995 200 5.0L GM (305cid) 1987-1995 200 5.0L GM (305cid) 1985-1986 228 (305c.i.) 1982-1984 228 4 BBL GM 1988-1995 230 MIE 4 BBL GM 305 1981-1995 230, 5.0L/LX MIE (305c.i.) 1981-1986 260 MIE GM 1987-1995 260, 350MAG 5.7L SKI/ALPHA/BRAVO (350cid) 1982-1994 260, 350MAG 1985-1989 300, 320EFI (350c.i.) 1982-1987 330 GM 454 1981-1992 330, 340, 7.4L MCM & MIE(454cid) 1986-1987 350 MAG ALPHA GM 1999-2001 350 MAG HORIZON MIE 1991-1996 350 MAG SKI GM 1998-2001 350MAG MPI (Gen+) & MIE (Gen+) 1998-2001 350MAG MPI MIE (GEN+)(350c.i.) 1999-2001 350 MAG MPI SKI (Gen+) 1991-1996 350MAG SKI 1991-1997 50MAG SKI 1994-2001 350MAG, 5.7L/LX ALPHA 1985-1987 370 TRS 1987-1989 420 1995-1996 450 1986-1997 454MAGALPHA 1992-1994 465 1998-2001 5.0L Alpha & Bravo (Gen+) 1999-2001 5.0L EFI (gen+) 1999-2001 5.7L EFI & (Gen+) 1998-2017 5.7K MIE & SKI 1987-1995 5.7L SKI 1987-1997 5.7L SKI 1998-2001 5.7L SKI 1994-1999 500 1999 500 (gen+) 1990-2001 500BULLDOG 1990-1993 502MAG 1991-1995 525SC 1996-1999 525SC 1991-1993 600 SC 1993-2001 600 SC 1990-1996 8.2L GM MPI MIE 1993-1998 800 SC 2000-2001 MX 6.2L MPI (377c.i.) Replaces: 18-5273 71780 805759Q3 805759T3