GM 1-Piece Rear Main Seal 168 Tooth Flywheel

The GM 1-Piece Rear Main Seal 168 Tooth Flywheel from Blueprint Engines is engineered for serious engine builders and mechanics tackling high-performance General Motors applications. This one-piece design eliminates the traditional two-piece seal configuration, reducing potential leak points and improving crankshaft reliability under demanding conditions. Whether you're rebuilding a stroker motor, upgrading a stock platform, or assembling a custom engine package, this flywheel serves as a critical foundation component that directly impacts engine longevity and oil retention integrity.

The 168-tooth design supports modern GM engine control systems and provides the precise reluctor ring pattern required for accurate spark timing and fuel injection management. The one-piece rear main seal integration eliminates the dual-seal vulnerability that plagues traditional two-piece designs—a common source of slow leaks in high-mileage or heavily modified engines. Blueprint Engines' manufacturing standards ensure proper surface finishing and concentricity, critical for seal seat accuracy and preventing oil seepage along the crankshaft. The robust construction handles both naturally aspirated and forced-induction applications, making it suitable for street performance, competition builds, and long-term reliability-focused restorations.

This flywheel is ideal for LS-series, small-block, and big-block GM engine platforms where OEM-spec or modern EFI compatibility is non-negotiable. Mechanics and engine builders appreciate the reduced assembly complexity and improved peace of mind that comes with a one-piece design—fewer opportunities for installer error and fewer potential leak pathways mean longer intervals between oil changes and less time troubleshooting mysterious drips. Proper installation requires attention to crankshaft runout, dowel pin alignment, and fastener torque specifications; following GM service procedures ensures optimal performance and seal longevity.