MSD Ultimate HEI Performance Upgrade Kit for Early GM V8 Engines 8501

If you're running an early GM V8 with stock HEI ignition, you're leaving serious horsepower on the table. The MSD Ultimate HEI Performance Upgrade Kit (8501) replaces weak OEM components with race-proven electronics that deliver 50% higher spark energy, especially critical at elevated RPM where ignition efficiency typically degrades. This complete system swap—including the HEAT Digital module, high-saturation coil, heavy-duty cap and rotor—transforms your distributor into a reliable, high-output ignition capable of supporting aggressive tuning and consistent performance.

Installation is straightforward for anyone comfortable working with basic ignition components. All necessary parts arrive ready to bolt into your existing distributor housing, making this an efficient upgrade path versus a full distributor replacement.

• 45,000V coil output
• In-cap coil design
• HEAT Digital HEI module included
• 50% higher coil drive current
• Heavy-duty cap and rotor
• Rynite distributor cap
• HEI 4-pin module type
• Adjustable rev limiter
• Red cap and dust cover
• Plastic coil dust cover
• No vacuum advance
• MSD part #8501