MSD Distributor Hole Plug

MSD Pro-Billet Distributor Hole Plug: Precision Engineering for Crank Trigger Builds

When you convert a small block or big block Chevy to a front-drive distributor or crank trigger ignition setup, the original distributor bore doesn't just disappear — it becomes an oil leak waiting to happen and a lubrication liability that needs a purpose-built solution. That's exactly what the MSD Distributor Hole Plug was designed to address. Rather than cobbling together a generic plug, MSD engineered the Pro-Billet Distributor Hole Plug (PN 8513) as a true system component, machined and spec'd to work in harmony with MSD's broader ignition ecosystem.

Why This Part Exists: The Crank Trigger Connection

MSD's front-drive distributor lineup created a specific need for a precision distributor hole plug. When running an MSD crank trigger system on a wet sump Chevy V8 — covering the 305, 350, 400, and 454 displacements — the factory distributor bore must be properly filled and sealed to maintain oil pressure and ensure correct cam gear lubrication. A poorly designed plug can starve the camshaft gear of oil or fail to maintain pressure in modified blocks. MSD's solution is anything but a simple cap.

Key Features of the MSD Pro-Billet Distributor Hole Plug

• CNC Machined Billet Aluminum Housing: The plug is housed in a CNC machined billet aluminum body, supplied with a bronze gear — the same Pro-Billet construction philosophy found across MSD's performance distributor lineup.
• Adjustable Slip Collar: An adjustable slip collar mounting flange accommodates engines with modified deck heights, ensuring correct installation depth — a critical detail for anyone running a stroked or decked block.
• Special Oil Tract for Enhanced Lubrication: A special oil tract improves lubrication to both the distributor and cam gear, protecting components that are often overlooked during high-performance builds.
• QPQ-Coated Polished Steel Shaft: The plug includes an oversized polished steel shaft with a QPQ coating, guided by a sealed ball bearing and an extra-long sintered bushing for long-term durability under race conditions.
• O-Ring Seal Compatibility: O-ring seals can be added to modified blocks to enhance oil pressure control, making this plug suitable for both stock and heavily modified engine combinations.
• Crank Trigger Requirement: This plug must be used with an MSD Crank Trigger, making it the natural complement to MSD's crank trigger ignition kits.

The MSD Difference in Every Component

MSD Ignition was the first company in the world to experiment with Multiple Spark Discharge for the ignition system of internal combustion engines in 1970. That engineering-first culture has carried through to every product bearing the MSD name — including supporting components like the distributor hole plug. From iconic 6AL ignition boxes to legendary Pro-Billet distributors and Super Conductor 8.5mm plug wires, MSD brings professional grade ignition components to any ride, from professional racing to daily drivers. The Pro-Billet Distributor Hole Plug reflects that same commitment: it's not just a blank-off plate, it's a machined, lubrication-optimized component designed to maintain the integrity of your entire ignition and valvetrain system.

For builders swapping to a full MSD ignition system, the Pro-Billet Distributor Hole Plug rounds out a complete, cohesive setup — ensuring that every aspect of the conversion, down to the distributor bore, meets the same precision standards as the rest of your ignition components. Browse all Distributor Hole Plugs to find the right fit for your application.