Optispark Distributor Vacuum Harness – LT1/LT4 (1993–1997 B/D/F-Body)

Vacuum harness for LT1 and LT4 engines equipped with a ventilated Optispark distributor, found in B-, D-, and F-body vehicles including the Camaro, Firebird, Impala SS, Fleetwood, Caprice, and Roadmaster. Replaces discontinued GM part number 12555323.

⚠️ Important: This harness is not compatible with Corvettes.
→ Click here for the Corvette-specific harness.

Upgrade your worn or heat-damaged vacuum harness assembly with our high-quality replacement. Our assembly includes the correct micron filter, check valve, fitting, and hose to suit GM ventilated Optispark distributors.  The check valve and filter match the original micron rating and are constructed from Viton material for enhanced durability. Additionally, the check valve features an integral orifice to help prevent cap implosion.

Key Features:

• Optimized Vacuum Flow: Our harness assembly is designed with the correct vacuum orifice, ensuring optimal vacuum flow without risking distributor damage.
• High-Quality Construction: While not original equipment from the manufacturer, our harness is crafted to closely match original specifications and appearance. We use high-quality vacuum hoses and fittings for durability and reliable performance.

Please note: Minor variations may occur due to component availability.

Installation Tips:

Attaching the vacuum hose to the distributor cap can be challenging when the ambient temperature is below 85°F. To ease installation, we recommend using a non-silicone-based lubricant, such as WD-40 or CRC.