RLP HEI Spark Plug Wire Set for V8 — 8mm Black Silicone Jacket, 90° Boots, Replaces 5553

RLP HEI Universal Spark Plug Wire Set delivers eight 8.0mm silicone-jacketed wires with 90-degree boots designed for V8 engines using GM HEI or HEI-style distributors.

These plug wires are built to replace part 5553 and provide a reliable ignition connection for many small- and big-block V8 engines when paired with an HEI distributor. Constructed with an 8.0mm spiral-core conductor and a heat- and oil-resistant silicone jacket, the set is intended for classic American V8s and conversions that use an HEI-type distributor. This is not for coil-on-plug (COP) or factory distributorless ignition systems.

Which engines will this wire set work with?

The RLP set is compatible with V8 engines that have a GM HEI or HEI-style distributor, covering a wide range of Chevrolet, GMC, Pontiac, Oldsmobile, Buick, Cadillac, Ford and Chrysler V8s when converted to HEI. Compatibility hinges on the distributor type rather than exact displacement—so check your ignition setup first.

• Covers Chevrolet SBC and BBC V8s (262–502) when using HEI distributors.
• Fits GMC, Pontiac, Oldsmobile, Buick and Cadillac V8s with HEI distributors.
• Supports Ford Windsor and FE V8s with HEI conversion and Chrysler LA V8 HEI conversions.
• Not suitable for COP units or factory distributorless systems.

How does the 8.0mm spiral core help performance?

The spiral-wound conductor balances conductivity with suppression to deliver a consistent spark while minimizing radio-frequency interference. It provides dependable electrical transfer in high-temperature engine bays without the higher noise issues of some solid-core designs.

• Spiral-core design for steady spark delivery and reduced interference.
• 8.0mm diameter for a compact yet durable profile.
• Engineered to resist common ignition noise affecting electronics and radios.

What protective features does the silicone jacket provide?

The thick silicone outer jacket offers strong insulation and defends the wires against heat, oil, and abrasion commonly encountered around classic V8 engines. That durable covering helps extend service life and keeps connections stable under demanding conditions.

• High-temperature silicone resists heat and engine bay exposure.
• Oil- and abrasion-resistant for longevity around valve covers and headers.
• Flexible material simplifies routing and prevents cracking with engine movement.

Is installation straightforward and what’s included?

Yes — the wires arrive ready to install and are pre-terminated with 90-degree spark plug boots to suit tight spaces near valve covers. The package includes eight wires sized at 8.0mm outer diameter, enough to wire a V8 with an HEI distributor.

• Package contains 8 x 8.0mm silicone spark plug wires with 90° boots.
• Pre-terminated for quick, tool-free installation in most setups.
• Designed for straightforward routing on classic V8 engines using HEI distributors.

Who is this for: RLP’s HEI Universal 8mm wire set is aimed at classic car owners, restorers, and hot-rodders who run V8 engines with GM HEI or HEI-style distributors or who have performed HEI conversions on Ford and Chrysler V8s. If you need a durable, heat-resistant wire set that balances performance and noise suppression for a distributor-equipped V8, this kit is a practical, plug-and-play replacement. Avoid this product if your vehicle uses coil-on-plug or a factory distributorless ignition system.