Late Buick Odd Fire V6 HEI Distributor - Short Shaft

• Self-contained HEI ignition with internal 65,000V coil, no external coil needed

• Direct fit for Buick 90° V6 odd-fire engines: 225 and early 231 CID

• Not for even-fire V6 or 3800 V6 — odd-fire distributor cap and trigger only

• Machined aluminum housing with included vacuum advance tool

Upgrade your Buick 90° V6 odd-fire engine — 225 or early 231 CID — with this 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 distributor is not compatible with later Buick even-fire V6 engines (1977-and-newer production) or the Buick 3800 V6/front-wheel-drive applications. Because Buick's odd-fire-to-even-fire changeover happened mid-way through the 1977 model year, verify your specific vehicle's engine type by its distributor cap style or engine VIN code rather than by model year alone if your vehicle is a 1977. 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.

What Is an HEI Distributor?
HEI (High Energy Ignition) replaces the external coil and breaker points used in factory Buick odd-fire ignition systems with a magnetic trigger and a high-output coil built directly into the distributor housing. Without points to wear or require periodic gap adjustment, timing holds more consistently, and this single unit replaces both the original distributor and ignition coil.

Performance Benefits
The 65,000-volt internal coil produces stronger spark output than a factory points-style distributor, supporting more consistent spark delivery across the RPM range on the Buick 90° V6 odd-fire platform. The magnetic trigger holds timing accurately without the point wear and drift common to older ignition systems. Mechanical and vacuum advance are both included, with a vacuum advance adjustment tool in the box so the timing curve can be tuned for the specific engine and driving conditions.

What engines and vehicles does this distributor fit?
This distributor fits Buick 90° 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 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 wrong shaft length will prevent proper engagement with the oil pump drive.

Does this distributor include an ignition coil?
Yes. The HEI ignition coil is built into the distributor cap, eliminating the need for an external ignition coil. A single 12-volt ignition power wire is all that is required.

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

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

What type of advance does this distributor use?
It features both mechanical (centrifugal) and vacuum advance. A vacuum advance adjustment tool is included to help fine-tune the ignition advance curve.

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 V6. Since both odd-fire and even-fire engines were produced during 1977, verify your engine casting number or VIN before purchasing.

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

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

What type of distributor gear is included, and does it matter?
A steel distributor gear is included. It is compatible with cast iron camshafts and many aftermarket steel camshafts. Verify compatibility if your engine uses a bronze or specialty cam gear.

Does this distributor have a tachometer output?
No. This distributor does not include a tachometer output or mechanical tachometer drive. Vehicles requiring a tachometer signal will need an appropriate electronic signal source or adapter.

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 timing will depend on 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 an alternator. It is not compatible with 6-volt systems, generators, or ballast resistors.

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