GM Performance 12564852 Exhaust Valve Stem Oil Seal

The GM Performance 12564852 is an OEM exhaust valve stem oil seal designed for GM small block V8 engines, including the legendary ZZ4 350 crate engine. This genuine GM part features positive-stop seal design with a steel body and Viton construction for superior heat resistance and durability in high-temperature exhaust valve applications.

Key Features:

• Positive-stop valve stem seal design for precise fitment
• Steel body with Viton sealing material for exhaust valve durability
• 5/16 inch valve stem diameter compatibility
• 0.630 inch outer diameter
• Direct replacement for GM ZZ4, Vortec, and Gen I small block engines
• Replaces GM part number 12558674

This exhaust valve seal is engineered to prevent oil from entering the combustion chamber while maintaining proper lubrication of the valve stem. The positive-stop design ensures consistent seal positioning and compression, making it ideal for both stock rebuilds and performance applications. Compatible with 4.3L V6, 5.0L, and 5.7L V8 engines found in Silverado, Sierra, Express, Savana, Astro, Safari, and S-Series vehicles from 1990-2014.

Note: Sold individually. Order the quantity needed for your application (typically 8 exhaust seals for V8 engines, or 16 total if replacing both intake and exhaust seals).