which company make the replacement secondary ignition system for the lt1 engine

 

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are you asking for a replacement for the opti? If that is the case, MSD makes a very nice opti replacement, it sells for $499, which is about $100 more expensive than a direct OEM replacement, but the MSD is a better system. The MSD is also better than the OEM for performance because the MSD is accurate up to 10,000 RPM as apposed to the stock 6,500.