8 pcs Forged Pistons with pins and rings for M113K engines with stock bore size and Darton or alternative iron sleeves.Includes 8 pistons, 8 piston pins, 16 pin locks, 8 piston ring sets, and 16 titanium spacers.with 0.001 mm tolerance for pin hole and 0.005 mm tolerance for diameter.Clearance between cylinder and skirt is 0.04–0.06 mm. Features: Phosphate coating on pistons to enhance oil adhesion for improved lubrication.Moly coating on piston skirts available as an option to reduce friction between piston and cylinder wall.Oil holes in the pin bore provide enhanced lubrication to piston pins, improving under temperature and rpm conditions.Lightweight design; when used with compatible H-beam connecting rods for M113K, total piston and rod assembly weight is reduced by approximately 250 grams per cylinder, contributing to improved engine response and higher rpm capability.Titanium spacers included for proper fitment in piston-guided engines, offering strength with reduced mass. Specifications: MB-041 Engine: M113K Compatible Models: E55 , CL55 , CLS55 , S55 , SL55 , G55 Piston Material: 4032 Connecting Rod Material: 4340 Bore Size: 97 mm Compression Ratio: Stock Compression Height: 30 mm Pin Diameter: 22 mm Overall Height: 51 mm Ring Dimensions: 97 x 1.2 + 1.75 + 2.0 mm Connecting Rod Length: 145.8 mm Piston Weight: 327 grams Compatibility Note: This is a third-party part.All brand/model references are for fitment purposes only. Model compatibility Designed for M113 5.0L and 5.5L engines including applications in E55 CL55 CLS55 S55 SL55 and G55 models fitment Forged construction Made from -strength 97mm forged aluminum for enhanced and resistance to -stress engine conditions Complete set Includes one full set of 8 pistons for complete engine rebuilds or performance in sleeved block configurations Optimized for performance Engineered to deliver power output and improved combustion efficiency in -performance V8 applications Direct replacement Designed as a direct fit for M113K engine platforms simplifying installation and the need for additional modifications Brand HatQvsPck Model HatQvsPck826 Exterior Aluminum Item Weight 7.1 ounces Manufacturer HatQvsPck Item model number HatQvsPck777 Product Dimensions 1.97 x 1.18 x 0.79 inches Manufacturer Part Number HatQvsPck777