This listing is for a set of (8) Flat head w/2-valve relief Coated skirt piston from Silvolite Pistons. Silvolite has been making pistons since 1922. These are Compatible replacements for early model 1972-1990 Ford 460 V-8 - 4.380" at +.020" Over bore. These can be used in Mercruiser boat engines equiped with the Ford 460. These are Not OE duplicate pistons. These replace the Oblong Oval receesed OE pistons.Use these as a performance upgrade. Use in sets only. Compression distance: 1.752". Ring grooves 5/64" 5/64" 3/16". Pins included 1.040" pin diameter-Press-fit only. For stock 6.605" length rods. Stock 3.850" stroke.