Chevy BB 348/409 V8 Pro Series Pro Billet Distributor

• Pro Billet distributor for Chevy W-Series Big Block 348 and 409 CID — external ignition box required

• Magnetic trigger with mechanical advance — 3 bushings and 4 springs for tunable timing on carbureted W-Series builds

• Adjustable slip collar for precise distributor phasing without rotating the housing

• Not compatible with Mark IV big blocks (396, 402, 427, 454) — W-Series exclusive

Pro Billet Distributor for the Chevrolet W-Series Big Block 348 and 409 CID V8

The Chevrolet W-Series big block is a distinct engine family — produced from 1958 through 1965 in 348 and 409 CID displacements — and it requires a distributor built specifically for it. This TSP Pro Series Pro Billet distributor is engineered for the W-Series and is not interchangeable with later Mark IV big block applications (396, 402, 427, 454). If you're building a performance 348 or 409 in an Impala, Bel Air, Biscayne, or C-series truck and want distributor-level control over your ignition system, this is the purpose-built Pro Billet solution for that engine.

The compact billet-style machined aluminum housing is precision-built for dimensional accuracy and provides additional clearance in performance engine bays where space around the distributor is limited. A magnetic trigger delivers a clean, consistent signal to your external ignition control box and coil across the full RPM range. Mechanical advance with three tunable bushings and four springs gives you direct control over your total advance curve — dial it in to your specific camshaft profile, carburetor setup, and intended use.

The adjustable slip collar allows you to fine-tune distributor phasing independently of the housing position — a key advantage when performing precision ignition tuning or working with a custom timing setup on a performance W-Series build. The steel gear is most compatible with cast iron hydraulic and solid flat-tappet camshafts; verify gear material compatibility with your camshaft manufacturer if your build uses a roller or specialty cam profile.

Applications
Designed exclusively for the Chevrolet W-Series Big Block Gen. I V8 — 5.7L / 348 CID and 6.7L / 409 CID. Not compatible with Mark IV big block engines (396, 402, 427, 454). Confirmed common vehicle applications include Chevrolet Impala, Bel Air, Biscayne, C10, C20, and K10. Suited for carbureted performance builds and high-output street applications on W-Series equipped vehicles from the 1958–1965 production era.

Q: What engines is this Pro Billet distributor designed for?
A: This Pro Billet distributor is designed exclusively for the Chevrolet W-Series Big Block Gen. I V8—5.7L (348 CID) and 6.7L (409 CID)—in carbureted applications. It is not compatible with later Chevrolet Mark IV big block engines, including the 396, 402, 427, or 454 CID.

Q: Will this distributor fit a 396, 402, 427, or 454 big block?
A: No. This distributor is specific to the Chevrolet W-Series engine family (348 and 409 CID). Mark IV big block engines use a different distributor design. If your engine is a 396, 402, 427, or 454, you'll need a distributor designed specifically for the Mark IV engine family.

Q: Do I need an ignition box with this distributor?
A: Yes. This is a Pro Billet distributor that requires an external CDI ignition control box to operate. It is not a Ready-to-Run distributor and does not contain an internal ignition module. An external ignition box and a compatible external ignition coil (35,000+ volts minimum) are both required and are not included.

Q: What is the difference between this distributor and the TSP W-Series Ready-to-Run distributor?
A: Both fit the same Chevrolet 348 and 409 W-Series engines, but they are intended for different ignition systems. This Pro Billet distributor requires an external CDI ignition box and external coil, making it ideal for high-performance builds already using a capacitive discharge ignition system. The Ready-to-Run distributor features an internal ignition module and only requires an external coil. This Pro Billet model also includes an adjustable slip collar for precise timing adjustment and mechanical advance tuning.

Q: What does the adjustable slip collar do?
A: The adjustable slip collar allows precise distributor positioning during installation and timing adjustment. Once the desired timing is achieved, the collar securely locks the distributor in place, helping maintain timing accuracy under high-RPM operation and engine vibration. It's a valuable feature for performance and racing applications where ignition stability is critical.

Q: What advance type does this distributor use?
A: This distributor uses mechanical (centrifugal) advance only and does not include vacuum advance. It comes with three advance bushings and four advance springs, allowing you to customize the mechanical advance curve for your engine combination.

Q: What coil and ignition box are compatible with this distributor?
A: This distributor is compatible with most magnetic-pickup CDI ignition boxes, including systems such as the MSD 6A, MSD 6AL, MSD 6AL-2, Mallory HyFire, Crane HI-6, and similar units. It also requires a compatible external ignition coil rated for at least 35,000 volts. Neither the ignition box nor the coil is included.

Q: Is the steel gear compatible with my camshaft?
A: This distributor includes a steel distributor gear that is best suited for cast iron hydraulic or solid flat tappet camshafts commonly found in W-Series engines. If your engine uses a roller or specialty camshaft, consult your camshaft manufacturer for the recommended distributor gear material before installation.

Q: What vehicles used the W-Series 348 and 409 big block?
A: Common Chevrolet W-Series applications include the Impala, Bel Air, Biscayne, El Camino, C10, C20, and other light-duty trucks produced between 1958 and 1965. Always verify your engine is a genuine 348 or 409 W-Series before ordering.

Q: Does my vehicle need a 12-volt electrical system?
A: Yes. This distributor requires a 12-volt electrical system with a functioning alternator. It is not compatible with 6-volt systems, generator-equipped vehicles, or ballast resistor ignition circuits.

Q: What is included with this distributor?
A: Included are the Pro Billet distributor, three advance bushings, four advance springs for mechanical advance tuning, an adjustable slip collar, and a color-matched spark plug wire retainer with mounting screws.

Q: What colors is this distributor available in?
A: This distributor is available in red, black, and blue finishes to complement your engine bay appearance.