OywhC Engine Oil Valley Block-Off Plugs for Non-AFM GM LSX & LT Engines — Stainless Steel Set of 10, Fits 2008–2023

OywhC Oil Valley Block Off Plugs are stainless-steel seals designed to permanently close oil passages on non-DOD/AFM GM LSX and LT engines (2008–2023), protecting oil pressure and simplifying engine swaps or conversions.

These oil valley plugs fit a wide range of GM V8 platforms — including LS1, LS2, LS3, LS7, L83 and LT-series motors — that do not use Displacement on Demand/AFM systems. Built from corrosion-resistant stainless steel, the ten-piece kit supplies enough plugs for one engine with two extras for spares or future maintenance. They’re intended for mechanical sealing of unused oil galleries during conversions, repair work, or when disabling AFM/DOD components, and install with simple tapping and an integrated removal thread.

Which engines and model years work with these plugs?

These plugs are engineered for GM V8 engines from model years 2008 through 2023 that lack AFM/DOD systems. They cover both classic LSX variations and the newer LT family, matching the common oil gallery sizes used across those blocks.

• Compatible with LS1, LS2, LS3, LS7 and modern L83, LT1, LT4, LT5
• Fits 4.8L, 5.3L, 6.0L and 6.2L non-DOD/AFM engines
• Intended for blocks used in swaps, rebuilds, or AFM deletion jobs
• Not for engines that require original DOD/AFM components to function

How do I install the oil valley block off plugs?

Installation is straightforward: each plug is gently driven into the oil gallery hole until seated. A 4mm × 9mm threaded recess on the top allows later removal with a standard fastener if service or modification is needed.

• Seat plugs by tapping evenly until flush with the oil valley surface
• Use the 4mm × 9 thread for extraction or repositioning during maintenance
• Apply light thread locker or sealant only if extra security is desired
• Follow torque and clearance practices for surrounding components

What are the material and durability details?

Manufactured from a stainless-steel alloy, these plugs resist corrosion and mechanical wear common in engine compartments. Their robust construction helps maintain a reliable oil seal even under heat and vibration, reducing the risk of leaks where oil galleries are no longer in use.

• High-strength stainless steel resists rust and pitting
• Durable against thermal cycles and engine vibration
• Precision-machined to provide a snug, repeatable fit
• Kit contains 10 plugs: 8 required per engine plus 2 spares

Will these plugs affect oil pressure or engine operation?

When used on engines that do not require DOD/AFM oil passages, the plugs merely close unused galleries and have no adverse effect on normal oiling systems. They are not a substitute for repairs on engines that need the original AFM/DOD plumbing to operate correctly.

• Seal unused passages to prevent oil leaks and pressure loss
• Do not alter active oiling circuits when applied correctly
• Not suitable for engines that depend on AFM/DOD passages for function
• Always verify engine configuration before installation

Who is this for: This OywhC kit is aimed at mechanics, engine builders, and DIY enthusiasts performing LSX or LT engine swaps, AFM/DOD deletions, or restorations where oil galleries must be sealed. It’s a practical choice for anyone needing durable, corrosion-resistant plugs that are simple to install and serviceable without specialized tools.