Genuine GM Parts 12661074 - Gen V LT Oil Gallery Plug

Description

Ensure proper internal oil routing and protect critical engine bearings with the authentic GM Genuine Parts Gen V LT Rear Oil Gallery Barbell Diverter Plug (Part # 12661074). Located at the rear of the engine block behind the rear cover, this factory original-equipment diverter plug directs pressurized oil flow from the pump directly through the oil filter before sending clean, filtered oil throughout the engine oil galleries.

A missing, damaged, or improperly seated oil gallery plug will allow unfiltered oil or critical pressure to bypass the main oil circuit, leading to severe pressure drops and catastrophic bearing failure. Whether you are assembling a fresh short block, completing a camshaft upgrade, or performing a comprehensive Gen V rebuild, installing a brand-new factory barbell plug ensures reliable oil passage sealing straight out of the box.

Product Highlights & Features

• Genuine GM OEM Quality: Designed, engineered, and validated to rigorous General Motors standards for factory durability and fitment.
• Critical Oil Routing: Forces unfiltered oil from the oil pump through the oil filter before entering the primary oil galleries and bearing circuits.
• Factory Press-In Fit: Direct drop-in replacement with integrated sealing O-ring for proper fitment in OEM engine block tolerances.
• Essential Engine Rebuild Detail: Mandatory service item when cleaning or prepping bare engine blocks, assembling rotating assemblies, or refreshing high-mileage blocks.

Engine Compatibility & Vehicle Applications

• Engine Platforms: GM Gen V LT gasoline V8 and V6 engines (5.3L, 6.2L, and 6.6L):
  • Car & Performance: LT1, LT4, LT5, and LT2
  • Truck & SUV: L83, L84, L82, L8B (5.3L), L86, L87 (6.2L), and L8T (6.6L)
  • V6 Applications: LV3 (4.3L) & 12634256
• Vehicle Fitment:
  • 2014+ Chevrolet Corvette (C7 & C8)
  • 2016-2024 Chevrolet Camaro SS / ZL1
  • 2016–2019 Cadillac CTS-V & 2022+ CT5-V Blackwing
  • 2014-2026 Chevrolet Silverado / GMC Sierra 1500 / 2500 / 3500 HD
  • 2015-2026 Chevrolet Tahoe, Suburban, GMC Yukon, and Cadillac Escalade
• Attachment Type: Press-in rear engine block galley
• GM Part Number: 12661074

Engine Builder Tech Note

Always inspect the rear oil gallery bore for cleanliness and burrs prior to installation. Lubricate the O-ring with fresh engine oil or assembly lube before gently tapping the barbell plug flush into the rear block galley to prevent pinching or cutting the seal.