Chevy Corvette V8 HEI Distributor with Mechanical Tach Drive

The TSP HEI Distributor with Mechanical Tach Drive is the correct ignition upgrade for Chevrolet small block and standard-deck big block V8 applications that use 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 factory-style cable-driven tachometers found in the Corvette C2 (1963–1967), Corvette C3 (1968–1982), and other GM applications with mechanical tach setups.

If your vehicle does not use a cable-driven mechanical tachometer, the standard TSP Chevy HEI distributor (without tach drive) is the correct unit. Not all Camaro, Chevelle, Nova, or Impala applications used mechanical tachometers — verify your vehicle's tachometer type before ordering. The mechanical tach drive provision on this distributor is non-functional on vehicles with electronic tachometers and adds no benefit.

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 used in many performance-era GM vehicles, most notably the Corvette C2 (1963–1967) and Corvette 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. Only order this tach drive version if your vehicle's tachometer uses a physical cable connection to the distributor.

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.

COMPATIBLE WITH
CHEVROLET SMALL BLOCK V8 GEN. I / BIG BLOCK V8 (STANDARD DECK)
• 4.6L / 283 in³
• 5.4L / 327 in³
• 5.7L / 350 in³
• 6.6L / 400 in³
• 6.5L / 396 in³
• 6.6L / 402 in³
• 7.0L / 427 in³
• 7.4L / 454 in³

NOTES
• Fits Chevrolet small block Gen. I and standard deck big block V8 engines with mechanical tach drive provision.
• Designed exclusively for Corvette applications using a cable-driven mechanical tachometer.
• Not compatible with tall deck big block Chevy engines.
• Not compatible with Camaro, Chevelle, Nova, Impala, or truck applications — those vehicles do not use mechanical tach drive distributors.
• This distributor is designed for a 12 volt electrical system with an alternator. 
• It is not compatible with a generator and cannot be used with a ballast resistor.
• Verify distributor gear compatibility with camshaft material before installation.

COMMON VEHICLE APPLICATIONS
Chevrolet Corvette C1 (1953–1962)
Chevrolet Corvette C2 (1963–1967)
Chevrolet Corvette C3 (1968–1982)

SPECIFICATIONS
Trigger Type: Magnetic
Advance Type: Mechanical And Vacuum
Color: Available in Red, Black, Blue, Clear
Terminal Gender: Male
Mechanical Tach Drive: Yes
Slip Collar: No
Coil Included: Yes
Coil Type: Internal
Coil Output: 65000 V
Gear Material: Steel
Housing Material: Machined Aluminum
Ignition Box Required: No
Marine Use: No
Cylinders: 8
Vacuum Advance Adjustment Tool: Included
Installation Instructions: Included