SBC BBC V8 Chevrolet HEI Distributor Black Cap Billet Aluminium Built-In Ignition Module & Coil

• Fits Chevrolet Gen. I small block 262–400ci and Mark IV big block 396–454ci engines - Designed for carburetted, standard-deck applications.
• Powerful internal 65,000-volt HEI coil - Provides a strong, consistent spark without requiring an external ignition coil.
• Self-contained large-cap HEI design - The coil, ignition module, magnetic pickup, cap and rotor are integrated into one distributor.
• Simple switched 12-volt connection - No external ignition box, condenser or ballast resistor is required.
• Adjustable mechanical and vacuum advance - Allows the ignition curve to be tuned for the engine combination and intended use.
• CNC-machined billet aluminium housing - Provides accurate fitment, strength and stable distributor operation.
• Hardened steel internal components and dual-bushing construction - Designed for durability and consistent shaft support.
• Not compatible with tall-deck Chevrolet big blocks, LS engines or computer-controlled ignition systems.

HEI Distributor for Chevrolet Small Block and Big Block V8

The GASO Peak Performance HEI Distributor is a complete, self-contained ignition upgrade for carburetted Chevrolet Gen. I small block and standard-deck Mark IV big block V8 engines. It combines the ignition coil, high-output ignition module, magnetic pickup, distributor cap and rotor into a single large-cap HEI assembly, eliminating the need for a separate coil, ignition box, condenser or points system.

Suitable for Chevrolet small block engines from 262ci through to 400ci and Mark IV big block engines from 396ci through to 454ci, this distributor offers broad compatibility across classic Chevrolet passenger cars, muscle cars, hot rods, commercial vehicles and performance engine conversions.

At the centre of the distributor is a powerful internal 65,000-volt HEI coil. The high-output coil provides the spark energy required for dependable ignition across a wide operating range, helping support easier starting, stable idle quality, clean throttle response and consistent combustion under load. This makes the distributor suitable for everything from a largely standard street engine to a modified, higher-compression or performance-oriented carburetted combination.

Installation is simplified through the integrated HEI design. A full switched 12-volt supply is connected directly to the distributor's battery terminal, while a separate tachometer terminal is available when an electronic tachometer is fitted. No external coil or ignition control box is required.

Everything You Need Under One Cap

Traditional points-style ignition systems use several separate components and are subject to contact wear, adjustment changes and timing drift. The GASO HEI distributor replaces the mechanical points arrangement with a maintenance-free magnetic pickup trigger and electronic ignition module.

The magnetic pickup generates a consistent trigger signal without physical contact between ignition points. This removes the regular points adjustment and replacement associated with older distributor designs while helping maintain more stable ignition timing over extended use.

The large-cap HEI configuration also increases the spacing between distributor cap terminals. Solid brass cap terminals provide a reliable electrical path from the internal coil and rotor to the spark plug leads, helping deliver consistent spark energy to each cylinder.

65,000-Volt Internal HEI Coil

The internal 65,000-volt HEI coil is designed to provide a strong and dependable spark without the need to mount and wire a separate ignition coil. The integrated coil sits inside the top of the distributor cap, creating a compact, self-contained ignition system with fewer external components and fewer potential wiring connections.

A stronger and more consistent ignition spark can be particularly beneficial when starting a cold engine, operating under increased cylinder pressure or running a modified engine with a larger carburettor, higher compression ratio or more aggressive camshaft.

Actual ignition performance will also depend on the engine condition, spark plug type and gap, plug leads, fuel mixture, compression ratio, ignition timing and charging-system voltage.

Adjustable Mechanical and Vacuum Advance

The distributor includes both mechanical and vacuum ignition advance systems. These systems allow ignition timing to change according to engine speed and operating load rather than remaining fixed at the initial timing setting.

Mechanical Advance

Mechanical advance increases ignition timing progressively as engine speed rises. Correct mechanical advance allows the ignition curve to be matched more closely to the engine's compression ratio, camshaft, cylinder heads, fuel quality, vehicle weight and intended RPM range.

Vacuum Advance

Vacuum advance adds ignition timing during light-load and cruising conditions when manifold or ported vacuum is available. When correctly connected and adjusted, vacuum advance can help improve part-throttle response, cruising efficiency and general street drivability.

Engines with heavily modified camshafts, low idle vacuum or specialised competition combinations may require adjustment, restriction or disconnection of the vacuum advance. The correct arrangement should be determined by the engine builder or tuner.

Strong Billet Aluminium Construction

The distributor housing is CNC machined from billet aluminium for strength, dimensional accuracy and a precise fit in the engine block. Hardened steel internal components and dual-bushing shaft support help maintain distributor shaft stability and consistent rotor alignment during operation.

Accurate shaft support is important because excessive movement can affect the relationship between the magnetic pickup, reluctor, rotor and distributor cap terminals. The rigid housing and supported shaft design help maintain stable operation throughout the engine's operating range.

Performance and Drivability Benefits

Replacing an old points distributor, worn factory electronic distributor or incomplete aftermarket ignition system with a new self-contained HEI distributor can provide several practical benefits when the engine is correctly wired and tuned.

• Strong, consistent spark throughout the normal engine operating range
• Easier cold and hot starting
• Improved idle consistency
• Cleaner throttle response
• Reduced maintenance compared with mechanical points
• More stable ignition timing
• Adjustable mechanical and vacuum advance
• No separate ignition coil required
• No external ignition control box required
• No condenser or points adjustment required
• Simplified engine-bay wiring

The final result will depend on correct installation, sufficient electrical supply, suitable spark plugs and leads, appropriate initial timing, the total mechanical advance and the rate at which the advance is introduced.

Compatible Chevrolet Engines

Chevrolet Gen. I Small Block V8

Compatible with carburetted Chevrolet Gen. I small block V8 engines using the conventional rear-mounted Chevrolet distributor arrangement.

• 262ci — 4.3 litres
• 265ci — 4.3 litres
• 267ci — 4.4 litres
• 283ci — 4.6 litres
• 302ci — 4.9 litres
• 305ci — 5.0 litres
• 307ci — 5.0 litres
• 327ci — 5.4 litres
• 350ci — 5.7 litres
• 400ci — 6.6 litres

This includes many standard and modified small block combinations, such as 350-based stroker engines, provided the engine retains the conventional Gen. I Chevrolet distributor location and uses a compatible distributor drive gear.

Chevrolet Mark IV Big Block V8 — Standard Deck

Compatible with carburetted, standard-deck Chevrolet Mark IV big block V8 engines.

• 396ci — 6.5 litres
• 402ci — 6.6 litres
• 427ci — 7.0 litres
• 454ci — 7.4 litres

This distributor is not suitable for tall-deck Chevrolet truck big blocks, including tall-deck 366ci and 427ci applications.

Common Vehicle Applications

Depending on the engine, engine conversion, intake manifold, firewall clearance and surrounding components, this distributor may be suitable for carburetted Chevrolet V8 applications found in vehicles including:

• Chevrolet Camaro
• Chevrolet Chevelle
• Chevrolet Malibu
• Chevrolet El Camino
• Chevrolet Nova
• Chevrolet Impala
• Chevrolet Bel Air
• Chevrolet Biscayne
• Chevrolet Corvette
• Chevrolet Monte Carlo
• Chevrolet C10, C20 and C30 trucks
• Chevrolet K-series four-wheel-drive trucks
• Chevrolet Blazer
• Chevrolet Suburban
• Equivalent GMC C/K trucks and utility vehicles
• Hot rods and custom vehicles using Chevrolet SBC or BBC engines
• Street machines and engine-converted vehicles
• Carburetted race and performance applications

Vehicle listings are provided as a general application guide only. Chevrolet vehicles were produced with numerous engine, ignition and accessory combinations, and many older vehicles have since undergone engine conversions or other modifications. Confirm the installed engine family, electrical system, distributor drive arrangement and physical clearance before ordering.

Ideal for Street, Restoration and Performance Builds

The broad SBC and BBC compatibility makes this HEI distributor suitable for a wide range of Chevrolet engine projects.

Standard and Mild Street Engines

On a standard or mildly modified 283, 305, 327 or 350, the HEI system provides a practical replacement for an ageing points distributor or worn original electronic distributor. The integrated design simplifies the ignition system while retaining vacuum advance for normal street use.

Stroker and Modified Small Blocks

The distributor can also be used with many carburetted stroker and performance small block combinations, including common 350-based builds, provided the engine uses the conventional Gen. I distributor mounting arrangement and the distributor gear material is suitable for the camshaft.

Big Block Street and Performance Engines

For standard-deck 396, 402, 427 and 454 Mark IV engines, the high-output internal coil and adjustable advance systems make the distributor suitable for street, muscle-car, hot-rod and performance applications. Higher-compression engines and combinations using aggressive camshafts should be professionally tuned to establish the correct initial timing, mechanical advance curve and total timing.

Restoration and Restomod Applications

This distributor is also an effective upgrade for restorations and restomods where ease of maintenance and dependable electronic ignition are more important than retaining a visually original points-style ignition system. The black cap provides a restrained appearance that suits a wide range of engine-bay styles.

Specifications

Electrical Requirements

This distributor is designed to operate from a full switched 12-volt electrical supply. The main ignition feed must provide battery voltage while the ignition switch is in both the start and run positions.

• Use a full switched 12-volt ignition supply.
• Do not connect the distributor through a ballast resistor.
• Do not use the original resistance wire from a points-style ignition system.
• Do not connect the distributor to a reduced-voltage coil feed.
• Ensure the distributor receives power while the engine is cranking and while it is running.
• Use appropriately sized automotive wire and secure electrical terminals.
• Confirm that the engine and battery have clean, low-resistance earth connections.
• Use the separate tachometer terminal only for a compatible electronic tachometer signal.

Although commonly described as a one-wire HEI distributor, this refers to the single switched 12-volt wire required to operate the ignition system. A second connection will be required when an electronic tachometer is used.

Important Distributor Gear Compatibility

The supplied steel distributor gear is generally compatible with many conventional cast iron hydraulic and solid flat-tappet camshafts. It must not be assumed to be suitable for every aftermarket camshaft.

Roller camshafts and specialised billet camshafts may require a compatible melonised, bronze, composite or other manufacturer-specified distributor gear. Using the wrong gear material can result in rapid wear or damage to the distributor gear and camshaft drive gear.

Always consult the camshaft manufacturer or engine builder to confirm the required distributor gear material before installation.

Installation Information

Distributor installation affects engine timing and must be performed carefully. Incorrect installation can prevent the engine from starting or may result in backfiring, poor performance, detonation or engine damage.

1. Confirm that the engine is a compatible Chevrolet Gen. I small block or standard-deck Mark IV big block.
2. Disconnect the battery before beginning installation.
3. Bring the engine to top dead centre on the compression stroke for cylinder number one.
4. Note the position of the existing distributor body and rotor before removal.
5. Confirm that the supplied distributor gear is compatible with the camshaft.
6. Apply a suitable high-quality engine assembly lubricant or gear lubricant to the distributor gear before initial installation.
7. Install the distributor while correctly engaging the camshaft gear and oil-pump drive.
8. Position the distributor body to provide adequate cap, firewall, intake-manifold and vacuum-canister clearance.
9. Connect a full switched 12-volt supply to the distributor battery terminal.
10. Connect the electronic tachometer to the tachometer terminal when required.
11. Install HEI-compatible spark plug leads in the correct Chevrolet firing order.
12. Start the engine and set the initial ignition timing using a timing light.
13. Check the mechanical advance, total timing and vacuum advance before driving the vehicle under load.

The distributor gear must be lubricated during initial installation. Do not install or operate the distributor with a dry gear.

Large-Cap HEI Clearance

This is a large-cap HEI distributor with the ignition coil mounted inside the cap. It requires more physical space than many factory points distributors and small-cap electronic distributors.

Before ordering, check the available clearance around the rear of the intake manifold, firewall, air cleaner, carburettor linkage, fuel lines, wiring, heater components and other engine-bay accessories. Clearance can vary significantly in engine-converted vehicles, hot rods and vehicles fitted with non-standard intake manifolds or engine mounts.

Spark Plug Leads

The distributor uses male HEI-style cap terminals. Spark plug leads must have compatible female HEI-style distributor boots and terminals. Leads designed only for an original points-style female distributor cap may not connect correctly.

Use good-quality suppression-type ignition leads that are suitable for a high-output HEI system. Route the leads away from exhaust components, sharp edges and moving parts, and separate adjacent leads where necessary to reduce the possibility of crossfire.

Chevrolet V8 Firing Order

The conventional Chevrolet Gen. I small block and Mark IV big block firing order is:

1-8-4-3-6-5-7-2

Distributor rotor rotation is clockwise when viewed from above. Always confirm the firing order required by the specific camshaft and engine combination, as certain specialised camshafts may use an altered firing order.

Not Compatible With

• Chevrolet 366ci tall-deck big block truck engines
• Chevrolet tall-deck 427ci truck engines
• Other tall-deck Chevrolet big block combinations
• Chevrolet LS-series engines
• Computer-controlled ignition systems
• Factory electronic fuel-injection systems requiring ECU-controlled ignition timing
• Applications requiring a distributor-mounted governor
• Applications requiring a mechanical tachometer drive
• Engines requiring a slip-collar distributor
• Six-volt electrical systems
• Electrical systems that supply reduced voltage through a ballast resistor or resistance wire
• Generator-equipped electrical systems that cannot provide a suitable stable 12-volt supply
• Marine applications requiring an ignition-protected or marine-certified distributor

Marine Use Warning

This distributor is not approved for marine use. Marine engine compartments can contain fuel vapour, and marine ignition components must be specifically designed and certified to reduce ignition risk. Do not install this distributor in a boat or other application requiring ignition-protected marine electrical equipment.

What Is Included

• GASO Peak Performance large-cap HEI distributor
• Internal 65,000-volt HEI ignition coil
• Integrated high-output ignition module
• Magnetic pickup trigger assembly
• Black HEI distributor cap with male brass terminals
• Rotor
• Vacuum advance unit
• Steel distributor gear
• Installation instructions

Spark plug leads, spark plugs, hold-down clamp, electrical wiring, timing light and installation tools are not included unless specifically shown or stated elsewhere in the listing.

Fitment Checklist

Confirm all of the following before ordering:

• The engine is a Chevrolet Gen. I small block or standard-deck Mark IV big block.
• The engine is carburetted and does not require ECU-controlled ignition timing.
• The big block is not a tall-deck 366ci or tall-deck 427ci truck engine.
• The engine does not use an LS-style ignition system.
• The vehicle has a suitable 12-volt alternator-based electrical system.
• A full switched 12-volt supply is available during both cranking and running.
• The ballast resistor or original resistance wire will be bypassed or replaced.
• The steel distributor gear is suitable for the installed camshaft.
• There is sufficient room for a large-cap HEI distributor.
• The spark plug leads have compatible HEI-style female cap terminals.
• A mechanical tachometer drive, slip collar or governor is not required.
• The application is not marine.

Important Notes

• Professional installation and ignition timing are recommended.
• Always confirm camshaft and distributor gear compatibility before installation.
• Lubricate the distributor gear with a suitable high-quality lubricant before initial use.
• Do not use a ballast resistor or points-style resistance wire in the distributor power circuit.
• Ensure the distributor receives a full switched 12 volts while cranking and running.
• Check total ignition timing and the complete advance curve, not only the initial idle timing.
• Verify large-cap distributor clearance before ordering.
• Vehicle application references are a guide and do not guarantee fitment to every model or modified vehicle.
• Not suitable for tall-deck Chevrolet big blocks, LS engines, computer-controlled ignition or marine use.