Ultra 40 Wire Set 8.5mm GM LS/LT 11.0

The MOROSO Ultra 40 Wire Set 8.5mm is a spiral-core spark plug wire kit engineered for GM LS and LT-series engines. This 8.5mm diameter wire set combines low-loss spiral core construction with straight plug boots and coil-style terminals, delivering reliable ignition performance and signal integrity across the complete LS/LT engine family. The red finish aids in engine bay identification and maintenance efficiency.

The 8.5mm wire diameter and spiral-core architecture minimize electromagnetic noise and voltage drop, critical factors in modern engine management where precise ignition timing directly affects fuel efficiency and emission control. The straight plug boots ensure consistent contact with modern spark plugs, while the coil-style terminal provides secure attachment to the ignition coil pack—eliminating the variability found in older distributor-based systems. This configuration is purpose-built for LS and LT platforms where factory specifications demand this exact wire gauge and terminal style.

Buyers performing LS or LT engine builds, restorations, or replacements rely on matched wire sets that maintain factory ignition characteristics without modification. This MOROSO kit serves both street and performance applications where changing spark plug wires shouldn't require rewiring the entire coil pack system. Whether you're running a traditional LS engine in a restoration or upgrading to a modern LT platform in a swap, this wire set integrates directly into your existing ignition architecture.

MOROSO is recognized in the GM performance community for ignition systems that preserve OEM electrical specifications while offering upgraded durability and thermal management. The Ultra 40 series represents a middle-ground choice—stepping up from budget wire sets while maintaining compatibility with stock and modified LS/LT platforms without custom fabrication.