Points to HEI Conversion

This project outlines converting a 1973 Chevrolet Impala from factory points ignition to a High Energy Ignition. This was done to add some simplification to maintenance, allow for removal of the points equipment such that it could be reverted back in the future, and done in a way to make it be equivalent to how the vehicle would have been if HEI had been offered. HEI did not come fully standard until the 1975 model year. This car has a 350 Small Block engine and a 2 barrel Rochester carburetor.¹ It does not have a tachometer. Correct Packard 56² style terminals crimps were sourced to allow for wiring into the bulkhead connector and proper mating with the factory terminals.

Contents

1. Tools
2. Parts
3. Process

Additional Resources

• On Stop Plates (GM Square Body Forum) & (Internet Archive)
• On Setting Timing (GM Square Body Forum) & (Internet Archive)
• Overview & Notes (Ray's Chevy Restoration Site) & (Internet Archive)
• Workshop Manuals (Detroit Iron)
• Old Car Manual Project (Page on Rochester 2G Carbs) & (Internet Archive)

Vendors & Suppliers

• I sourced the primary parts such as the distributor, SXL³ power wire, spark plug wires, and open barrel terminals from Summit Racing.
• Tools came from a mix of Harbor Freight, Walmart, Amazon, McMaster-Carr, and Home Depot.
• Consumables came from Walmart, Amazon, and McMaster-Carr.
• Technical information was found at various online resources and from RockAuto's literature section for the vehicle.

Footnotes

1. Additional info on this car can be found on automobile catalog. ↩

2. Packard 56 series ended up under the GM / Delphi brand and now eventually under the Aptiv brand. While you can get 1 to 4 pin connector housings you cannot source the bulkhead connector housings. The geometry on the bulkhead connector is simple enough that it could resin 3d printed if ever needed to be replaced. ↩

3. Quick overview of SXL vs other insulation. ↩