Description Reviews Wiseco pistons are a high quality forged stock replacement piston. These pistons can be used with stock or aftermarket connecting rods (but not with the Carrillo rods without machine work to the rods). These come in the standard 8.5:1 compression ratio for they MINI, and have the bore options of standard (77mm) and 0.020in over bore (77.5mm). They are forged, so they'll handle any amount of boost you can throw at them, but lightweight so all that power gets to the ground. Sold in sets of 4 and include pistons, rings and wrist pins. World renowned for our work building race winning pistons, Wiseco utilizes experience from a diverse background of the most sophisticated sport compact engines. Wiseco’s Sport Compact Pro Tru line creates the best value in forged pistons today. These American made pistons are forged and machined by skilled Ohio craftsmen with state-of-the-art forging presses and CNC machines. By using dedicated forgings specific to the final piston shape, Pro Tru pistons are stronger and lighter than industry standards. Pro Tru sets include plasma moly 1/16, 1/16, 3/16 pre-gapped ring packages which provide excellent seal, friction reduction, and long life. Pro Tru pistons also come in a variety of volumes that allow the engine builder to choose the exact compression ratio required for their engine. Details: Description: Pro Tru Pistons; Sport Compact Series; Set of 4 Pistons; Recommended RingSet: 7700XX; Rings & Pins Included Comp Ratio:8.5:1 Stroke: 85.8 Bore: 77mm or 77.5mm Rod:131.5 Gram Weight: 246 Dome Volume: 0 FT Comp Height: 26.5