Chevy Corvette V8 HEI Distributor with Mechanical Tach Drive

• Includes mechanical tach drive — required for cable-driven Corvette and GM tachometer applications

• Fits SBC 262–400 and standard deck BBC 396–454 — tall deck BBC not compatible

• 65,000-Volt internal HEI coil — single 12V wire, no external coil or box needed

• Mechanical and vacuum advance — vacuum adjustment tool and instructions included

The TSP HEI Distributor with Mechanical Tach Drive is the correct ignition upgrade for Corvette applications using a cable-driven mechanical tachometer. Functionally identical to the standard TSP Chevy HEI distributor in ignition performance, this unit adds a mechanical tachometer drive provision on the distributor housing — the cable connection required to operate the factory-style cable-driven tachometers found in the Corvette C2 (1963–1967) and Corvette C3 (1968–1982) instrument clusters.

This distributor is designed for Corvette applications using a cable-driven mechanical tachometer. Cable-driven tachometers were standard equipment on the Corvette C2 (1963–1967) and C3 (1968–1982), and were used on later-production C1 Corvettes (1953–1962) as well — confirm your specific model year before ordering. If your vehicle uses an electronic tachometer — including Camaro, Chevelle, Nova, Impala, and truck applications, which do not use mechanical tach drive distributors — the standard TSP Chevy HEI distributor (without tach drive) is the correct and less expensive unit.

Engine fitment covers the full Chevrolet small block Gen. I family — 262, 283, 302, 305, 327, 350, and 400 CID — and the standard-deck Chevrolet big block family — 396, 402, 427, and 454 CID. This distributor is not compatible with tall-deck big block Chevy engines. Will not fit if a governor device is present in the distributor drive location.

The self-contained large-cap HEI design integrates the ignition coil, ignition module, cap, and rotor into a single unit, connecting to a single 12-volt source with no external coil, ignition box, or condenser required. The 65,000-volt internal HEI coil delivers substantially stronger spark than a factory points-style distributor, supporting easier cold starts, cleaner idle quality, and more consistent ignition performance. Both mechanical and vacuum advance are included, with a vacuum advance adjustment tool shipped with the distributor.

What Is a Mechanical Tach Drive and Do You Need One?
A mechanical tachometer drive is a provision on the distributor housing that accepts a tachometer cable — the same type of cable that connects a speedometer to a transmission output shaft, but for RPM measurement instead of vehicle speed. Cable-driven mechanical tachometers were standard equipment on the Corvette C2 (1963–1967) and C3 (1968–1982) instrument clusters. Without a mechanical tach drive on the distributor, a cable-driven tachometer has no signal source and will not operate.

If your vehicle uses an electronic tachometer that picks up signal from the ignition system electronically, you do not need this unit — the standard TSP Chevy HEI distributor without tach drive is the correct choice and is less expensive.

Performance Benefit
The 65,000-volt internal HEI coil delivers substantially stronger spark than a factory points-style or worn stock HEI distributor across the full RPM range. The magnetic pickup trigger holds timing accurately without the wear and drift that accumulates in points-based systems. Both mechanical and vacuum advance are included, and the vacuum advance adjustment tool allows the vacuum advance curve to be tuned for your specific engine combination and driving conditions.

What is a mechanical tach drive and why does the Corvette need one?
A mechanical tach drive is a provision on the distributor housing that accepts a tachometer cable, transmitting engine RPM to a cable-driven mechanical tachometer. Chevrolet Corvette C2 (1963–1967) and C3 (1968–1982) models originally equipped with cable-driven tachometers require this feature for the factory tachometer to operate. If your vehicle uses an electronic tachometer, a standard TSP HEI distributor without a mechanical tach drive is the correct choice.

How do I know if my vehicle uses a mechanical tach drive distributor?
Inspect your existing distributor or the back of the tachometer. If a cable runs from the distributor to the instrument cluster, similar to a speedometer cable, your vehicle uses a mechanical tach drive. If the tachometer receives its signal through an electrical wire, this distributor is not required.

What engines does this distributor fit?
This distributor fits Chevrolet Gen I Small Block V8 engines, including 262, 265, 267, 283, 302, 305, 307, 327, 350, 355, 383, and 400 CID applications, as well as standard-deck Chevrolet Gen II Big Block (Mark IV) V8 engines, including 396, 402, 427, and 454 CID. It is not compatible with tall-deck Big Block Chevrolet engines or applications using a governor in the distributor mounting location.

What Corvette years does this distributor fit?
This distributor fits the Corvette C2 (1963–1967) with 327 or 427 V8 engines, the Corvette C3 (1968–1982) with 350, 396, 427, or 454 V8 engines, and later-production C1 Corvettes (1953–1962) that were equipped with a cable-driven mechanical tachometer — not all C1 model years used this tach style, so confirm your specific vehicle's tachometer type before ordering. Confirm your specific engine is within the confirmed small block Chevy (SBC) or standard-deck big block Chevy (BBC) fitment range before ordering.

What is the difference between this distributor and the standard TSP Chevy HEI distributor?
The primary difference is the built-in mechanical tachometer drive. Otherwise, both distributors share the same HEI design, integrated 65,000-volt coil, magnetic pickup, mechanical and vacuum advance systems, and installation requirements. If your vehicle uses an electronic tachometer, the standard TSP HEI distributor without a mechanical tach drive is the appropriate choice.

Will this fit a tall-deck Big Block Chevy?
No. This distributor is designed for standard-deck Chevrolet Gen II Big Block (Mark IV) engines only. It is not compatible with tall-deck Big Block Chevrolet engines.

Does this distributor include an ignition coil?
Yes. The HEI ignition coil is integrated into the distributor cap, so no external ignition coil is required. Installation only requires a switched 12-volt power source.

Do I need an external ignition box or control module?
No. This HEI distributor contains an internal ignition control module and does not require an external ignition box, CDI unit, points, or condenser.

What is the coil output voltage?
This distributor features a high-output 65,000-volt ignition coil, providing a stronger spark than a factory points-style distributor for improved starting, idle quality, and throttle response.

What type of distributor gear is included?
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.

Do I need to set ignition timing after installation?
Yes. Base ignition timing must be set with a timing light after installation. Final timing specifications will vary depending on your engine combination, compression ratio, camshaft, and fuel 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 electrical systems, generator-equipped vehicles, or ballast resistors.