This is for a brand new OEM Sierra Mercury Mercruiser Piston Ring Set .030 inch 18-3941, replaces Mercruiser 39-67128 OMC/Volvo 328541 and Crusader 30185 Rings are sold by the pair. Qty 1 will do one piston Fits: 340 HP/7.4L W/BORG WARNER TRANS (GM) - 340 MIE W/B/W GM 454 V-8 1981-1987 330 HP ENGINE W/BORG WARNER - 330 GM 454 V-8 1982-1987 370 HP TRS ENGINE (CARD 37) - 370 TRS GM 454 V-8 1985-1987 350 INBOARD ENGINE - 350 MIE GM 454 V-8 1974-1976 420 / 425 - 425 (GEN. V) GM 454 V-8 1992-1993 330 ENGINE (G.M.) - 330 MIE GM 454 V-8 1977-1980 370/400/440/460 CYCLONE TRS ENGINE - 400 TRS GM 454 V-8 1980-1986 330 ENGINE (G.M.) - 330 GM 454 V-8 1977-1981 340 HP/7.4L W/BORG WARNER TRANS (GM) - 7.4l MIE W/B/W GM 454 V-8 1988-1992 370/400/440/460 CYCLONE TRS ENGINE - 370 TRS GM 454 V-8 1978-1985 370/400/440/460 CYCLONE TRS ENGINE - 460 TRS GM 482 V-8 1983-1986 325 ENGINE - 325 MIE GM 427 V-8 1968-1974 420 / 425 - 420 GM 454 V-8 1987-1989 454 MAGNUM BRAVO ENGINE - 454 MAG. BRAVO GM 454 V-8 1988-1992 7.4L TRANSMISSION W/HURTH (G.M.) - 7.4L MIE W/HURTH GM 454 V-8 1989-1992 7.4L BRAVO - 7.4L BRAVO GM 454 V-8 1988-1991 454 MAGNUM ALPHA ONE ENGINE - 454 MAG. ALPHA GM 454 V-8 1986-1988 370/400/440/460 CYCLONE TRS ENGINE - 440 TRS GM 454 V-8 1983-1986 May fit additional models to those listed above. Although your model may be listed above we always suggest that you compare the OEM number of the part for your engine to those listed below Returns of NEW ITEMS accepted in 30 days ONLY if they have NOT been installed and are in same condition as when they were shipped. If you are missing parts of the item or original packaging, item CANNOT be returned.