Forged Super Duty series for the Milwaukee Eight engine. With hard anodized crown and top ring groove to reflect heat and prevent ring to groove ''micro-welding''. The Line2Line abradable self-lubricating powder coating technique allows zero tolerance installation; final tolerance will be 0.003". The piston creates its own perfect tolerance during run-in; the coating automatically gives the tightest possible & perfect piston to cylinder fit for no piston rock and best possible ring seal. Note: Fits 107" M8 engines. Works with stock 4.375" stroke and stock unmodified heads. Aftermarket 4.25" bore cylinders are required. - 11.4:1 CR - Piston weight: OEM - Engine displacement: 124" - Bore: 4.25" - Stroke: 4.375" (stock 107" engine) - Ring pack: 1.5mm; 1.5mm; 3.0mm - Top land: .230 - Pin number: .9270x2.250x.180-SCR415H - Pin type: Floating - Pin diameter: .927" - Compression height: 1.155" - Crown Type: Dome - Crown (cc): -2cc - Alloy: Forged 4032 Alloy