Chevy 262 (4.3L) V6 HEI Distributor with Super Cap

• Super Cap HEI — larger cap for improved plug wire routing and reduced crossfire risk

• Fits GM 90° 4.3L (262 CID) V6 — carbureted applications only, not EFI or Vortec

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

• Not compatible with GM 60° V6 (2.8L/3.1L/3.4L) or computer-controlled ignition

The TSP Super Cap HEI Distributor for the GM 90° 4.3L V6 is a carbureted HEI ignition upgrade for the Chevrolet 262 CID (4.3L) 90-degree V6 — featuring a Super Cap design that provides a larger diameter distributor cap than the standard HEI version. The increased cap size creates greater physical spacing between the spark plug wire terminals, reducing the risk of crossfire between adjacent cylinder positions and improving plug wire routing in tighter engine bay configurations.

Super Cap vs. Standard Cap — What's the Difference?
The standard HEI cap on JM6521R and the Super Cap on this unit (JM6520R) are both large-cap HEI designs, but the Super Cap offers a wider cap diameter with more terminal spacing. The wider spacing between terminals reduces the risk of high-voltage crossfire — where voltage intended for one cylinder arc-jumps to an adjacent terminal — which can occur in high-performance or high-RPM applications, or when plug wires have developed increased resistance. The Super Cap also provides more physical clearance for routing 90-degree plug wire boots in tight spaces around the cap. If wire routing clearance and crossfire resistance are priorities in your build, the Super Cap is the correct choice. If a more compact cap profile is acceptable, the standard cap JM6521R is functionally equivalent at the same price.

Verify your ignition system before ordering. The 4.3L V6 transitioned from carburetor to Throttle Body Injection (TBI) EFI in approximately 1988 in most applications. This distributor is designed for the carbureted HEI ignition system only and is not compatible with TBI, CMFI, EFI, Vortec, or any computer-controlled ignition system.

Verify your V6 engine family before ordering. The GM 90° V6 (262 CID, small block-based) is not the same as the GM 60° V6 (2.8L, 3.1L, 3.4L). These two families require different distributors. If your engine is a 2.8L, 3.1L, or 3.4L, this distributor is not compatible.
The 65,000-volt internal HEI coil delivers stronger, more consistent spark than a stock or worn factory distributor across the full RPM range. Both mechanical and vacuum advance are included, with a vacuum advance adjustment tool shipped with the distributor.

Standard Cap vs. Super Cap — Which Version Is Right for Your Build?
TSP offers two HEI distributor options for the carbureted GM 90° 4.3L V6 — this Super Cap version (JM6520R) and a standard cap version (JM6521R). Both are HEI designs with an integrated 65,000-volt coil, the same engine fitment, and the same price. The difference is cap size.

The Super Cap features a larger diameter cap with greater spacing between the eight spark plug wire terminals. More spacing between terminals means a lower risk of crossfire — an arcing event where voltage intended for one cylinder jumps to an adjacent terminal rather than firing through the correct plug wire. Crossfire risk increases with higher coil output, worn plug wires, and high-RPM operation. For stock engines and street driving, both cap sizes work equally well. For builds with higher-output coils, performance plug wires, or sustained high-RPM use, the Super Cap's increased terminal spacing is a meaningful advantage. The Super Cap also provides more physical room for routing 90-degree plug wire boots, which can be useful in tighter engine bay configurations.

If neither cap clearance nor crossfire is a concern in your application, the standard cap JM6521R is the simpler choice. If plug wire routing clearance or crossfire resistance matters for your specific build, this Super Cap version is the correct unit.

Carbureted vs. EFI — Verify Before Ordering
The GM 90° 4.3L V6 was produced with a carburetor from approximately 1985 through 1987 in most light truck and van applications before transitioning to Throttle Body Injection (TBI) in approximately 1988. This distributor is for carbureted HEI ignition systems only. If your vehicle uses TBI, CMFI, Vortec, or any fuel injection system, this distributor is not compatible.

Performance Benefit
The 65,000-volt internal HEI coil delivers stronger, more consistent spark than a stock or worn factory 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, with a vacuum advance adjustment tool allowing the vacuum curve to be tuned for your specific combination.

What is a Super Cap and why would I choose it over the standard HEI cap?
The Super Cap is a larger-diameter HEI distributor cap with more physical spacing between the spark plug wire terminals than a standard HEI cap. The wider terminal spacing reduces the risk of crossfire—an arcing event where high voltage intended for one cylinder jumps to an adjacent terminal. This can occur with high-output coils, worn plug wires, or sustained high-RPM operation. The Super Cap also provides more room to route 90-degree spark plug wire boots around the cap. For stock engines and normal street driving, either cap size works. For performance builds, high-output coils, or applications where plug wire routing clearance matters, the Super Cap is the better choice.

What is the difference between this distributor and the standard TSP 4.3L V6 HEI (JM6521)?
These two distributors are identical in engine fitment, specifications, coil output, trigger type, advance system, price, and included components. The only difference is the cap. This listing (JM6520) features a Super Cap with a larger diameter and wider terminal spacing, while JM6521 uses a standard HEI cap. Choose the Super Cap for builds where reduced crossfire risk or improved plug wire routing clearance is a priority. Choose the standard cap for a more compact distributor profile.

What engines does this distributor fit?
This distributor fits the GM 90° V6—4.3L (262 CID)—in carbureted applications only. It is not compatible with GM 60° V6 engines (2.8L, 3.1L, or 3.4L), TBI, EFI, Vortec, or any computer-controlled ignition system.

Does this fit my 4.3L V6—how do I know if mine is carbureted or EFI?
The carbureted 4.3L V6 was used from approximately 1985 through 1987 in most applications. From approximately 1988 onward, GM transitioned most 4.3L applications to Throttle Body Injection (TBI). To verify, inspect your intake manifold. If you see a carburetor, your engine is carbureted and this distributor is compatible. If you see a TBI throttle body with fuel injectors, your engine uses EFI and this distributor is not compatible.

What is the difference between the GM 90° V6 and the GM 60° V6?
The GM 90° V6 (4.3L / 262 CID) is derived from the Chevrolet small block V8, with cylinder banks forming a 90-degree angle. It was used primarily in rear-wheel-drive trucks, vans, and SUVs. The GM 60° V6 (2.8L, 3.1L, and 3.4L) is a narrower, separate engine family used in front-wheel-drive and some rear-wheel-drive passenger cars. These two engine families require different distributors. If your engine is a 2.8L, 3.1L, or 3.4L, this distributor is not compatible.

Does this distributor include an ignition coil?
Yes. The ignition coil is built into the distributor cap as part of the HEI design. No external coil is required. The only external connection needed is a single 12-volt hot wire.

Do I need an external ignition box or control module?
No. The ignition control module is integrated internally within the distributor. No external ignition box, CDI unit, points, or condenser is required.

What is the coil output voltage?
This distributor produces 65,000 volts of coil output, delivering a stronger, more consistent spark than a stock or worn factory distributor for improved cold starts, idle stability, and throttle response.

What type of advance does this distributor use?
This distributor uses both mechanical (centrifugal) advance and vacuum advance. A vacuum advance adjustment tool is included to allow tuning of the vacuum advance curve for your specific application.

What type of distributor gear is included?
This distributor includes a steel distributor gear. It is most compatible with cast iron hydraulic or solid flat tappet camshafts. For roller camshaft applications, consult your camshaft manufacturer for the recommended gear material.

Do I need to set ignition timing after installation?
Yes. Set base ignition timing with a timing light after installation. For most carbureted 4.3L V6 applications, 6–10 degrees BTDC at idle is a common starting reference, though optimal timing will vary based on your engine combination and carburetor tune.

Is this 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 6-volt systems, generators, or ballast resistors.