Enginetech M41558-030 Moly Piston Ring Set GM Pontiac 455 V8 .030 Oversized

The Enginetech M41558-030 is a premium moly piston ring set engineered for the GM/Pontiac 455 cubic inch (7.5L) V8 engine. Designed for engines bored .030 in. (.75mm) over standard, this complete ring set provides a precise drop-in fit for a reliable engine rebuild.

Enginetech ring sets are manufactured in OE-quality facilities using top-grade materials including high-quality gray iron, ductile iron, and high-strength steel. The top compression ring features a plasma-moly face coating for superior wear resistance and improved ring seal, while the second ring is phosphate coated for enhanced durability.

Ring Set Specifications:

• Engine: GM/Pontiac 455 V8 (7.5L, 455 cu. in.), 1970–1976
• Oversize: .030 in. (.75mm) over standard
• Bore Size (at oversize): 4.150 in. (105.41mm)
• Number of Cylinders: 8
• Top Ring Thickness: 5/64 in. (1.984mm) — Plasma-Moly faced
• Second Ring Thickness: 1/16 in. (1.587mm) — Phosphate coated
• Oil Ring Width: 3/16 in. (4.762mm)
• Top Ring Material: Ductile iron with plasma-moly face coating

Key Features:

• Manufactured in OE-quality facilities for consistent fit and performance
• Plasma-moly top ring face coating for reduced friction and extended service life
• Oil ring expanders engineered to prevent overlap during installation
• Complete set covers all 8 cylinders for one engine rebuild
• Drop-in fit — no file-fitting required

This ring set is a trusted choice for professional engine builders and experienced rebuilders restoring or refreshing classic GM and Pontiac big-block V8 engines.