Late Buick Odd Fire V6 HEI Distributor - Short Shaft

• 65,000-volt internal coil eliminates external coil and ignition box wiring

• Magnetic trigger holds timing accurately without points wear or drift

• Short shaft fits Buick 231 odd-fire passenger-car applications (1975–1977)

• Mechanical & vacuum advance included, with adjustment tool in the box

Upgrade your Buick 90° V6 odd-fire engine — 3.8L/231 CID, 1975–1977 — with this short-shaft HEI-style distributor, built around a magnetic trigger and a 65,000-volt coil housed directly in the unit, so there's no external coil or ignition box to wire in separately. This distributor is designed specifically for odd-fire engines and uses an odd-fire distributor cap and trigger configuration that will not interchange with later even-fire units.

This is a short shaft distributor for 231 odd-fire passenger-car applications only — not compatible with the long-shaft 225 Dauntless/Jeep application, even-fire Buick V6 engines, or the Buick 3800 V6/front-wheel-drive applications. Because Buick's odd-fire-to-even-fire changeover happened mid-year in some model years, verify your specific vehicle's engine type by its distributor cap style or engine VIN code rather than by model year alone if you're uncertain.

The housing is machined aluminum with a steel drive gear best matched to cast iron hydraulic or solid flat-tappet camshafts. This distributor requires a 12-volt electrical system with an alternator; it is not compatible with generator-based charging systems or vehicles still running an active ballast resistor in the ignition circuit — the resistor should be removed or bypassed as part of installation. Mechanical and vacuum advance are both included, with a vacuum advance adjustment tool in the box.

Applications
Fits Buick 90° V6 odd-fire, short shaft: 3.8L/231 in³, 1975–1977, passenger-car applications only. Common on Buick Century, Regal, Skyhawk, Skylark, LeSabre, Oldsmobile Starfire, Delta 88, Omega, and Pontiac Sunbird, Firebird, Catalina, Grand LeMans, LeMans, Phoenix, and Ventura odd-fire V6 applications from this period. Not compatible with the 225/3.7L Dauntless Jeep application, which requires a long-shaft distributor (see TSP's long-shaft odd-fire unit).

Installation
Not compatible with even-fire Buick V6, Buick 3800 V6, or front-wheel-drive applications. Requires a 12-volt electrical system with an alternator; not compatible with generator-based charging systems, and any active ballast resistor should be removed or bypassed during installation. Verify engine type by distributor cap style or VIN code rather than model year alone if uncertain. Designed for carbureted ignition systems only.

What engines and vehicles does this distributor fit?
This distributor fits Buick 90-degree odd-fire V6 engines, including the 231 CID (3.8L) odd-fire used in 1975–1977 Buick, Oldsmobile, and Pontiac rear-wheel-drive passenger cars. It also fits the Dauntless 225 CID (3.7L) V6 with a slight intake manifold modification for distributor clearance. It is not compatible with even-fire Buick V6 engines, the Buick 3800, or front-wheel-drive applications.

What is the difference between the TSP short-shaft and long-shaft Buick odd-fire V6 HEI distributors?
The difference is distributor shaft length. The short-shaft version fits 1975–1977 Buick 231 odd-fire passenger car engines, while the long-shaft version fits 1966–1971 Dauntless 225 Jeep applications. Using the incorrect shaft length will prevent proper engagement with the oil pump drive.

Does this distributor include an ignition coil?
Yes. This HEI distributor features a high-output 65,000-volt internal ignition coil and an integrated ignition module. It uses a simple one-wire hookup and does not require an external ignition box or external coil.

Do I need an external ignition box or ignition control module?
No. The ignition control module is built into the distributor housing, so no external ignition box, CDI unit, points, or condenser is required.

What is the coil output voltage on this distributor?
This distributor produces up to 65,000 volts of spark output to provide improved starting, idle quality, and throttle response compared to a factory points ignition system.

What type of advance does this distributor use?
This distributor features both mechanical (centrifugal) and vacuum advance. A vacuum advance adjustment tool is included, allowing you to fine-tune the vacuum advance curve to suit your engine combination.

Does this distributor fit a 1977 Buick, Oldsmobile, or Pontiac with a V6?
It depends on the engine. This distributor fits only the odd-fire 231 CID V6. Because both odd-fire and even-fire versions were produced during the 1977 model year, verify your engine casting number or VIN before ordering.

Will this distributor fit the Buick 3800 V6?
No. This distributor is not compatible with any Buick 3800 (3.8L) V6 engine.

Does this distributor fit front-wheel-drive Buick or GM vehicles?
No. This distributor is designed exclusively for carbureted, rear-wheel-drive Buick odd-fire V6 applications.

What type of distributor gear is included, and does it matter?
This distributor includes a steel distributor gear, which is best suited for cast iron hydraulic or solid flat-tappet camshafts. If your engine uses a roller or other specialty camshaft, verify the recommended distributor gear material with your camshaft manufacturer before installation.

Does this distributor have a tachometer output?
Yes. Like other large-cap HEI distributors, this unit includes a tachometer terminal on the side of the distributor cap for connection to most factory and aftermarket electronic tachometers. It does not include a mechanical (cable-driven) tachometer drive.

Do I need to set ignition timing after installing this distributor?
Yes. Base ignition timing should be set with a timing light after installation. Final ignition timing should then be adjusted to match your engine combination and tuning requirements.

Is this distributor compatible with a 6-volt system or generator?
No. This distributor requires a 12-volt electrical system with a charging alternator. It is not compatible with generator-equipped vehicles or ignition systems that use an active ballast resistor.

Does the Dauntless 225 installation require any modifications?
Yes. Installation on the Dauntless 225 CID V6 requires a slight intake manifold modification to provide distributor clearance. No modification is required when installing this distributor on 1975–1977 Buick 231 CID odd-fire passenger car applications.