For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition
65 WarningElectronic Ignition System Description Engine Control
The electronic ignition system produces and controls a high-energy secondary spark.This spark is used to ignite the compressed air/fuel mixture at precisely the correcttime. This provides optimal performance, fuel economy, and control of exhaust emissions.This ignition system uses an individual coil ...