MSD 89121 Dual Ignition Tach Adapter
MSD 89121 Dual Ignition Tach Adapter. MSD Part Number 89121. When you install an MSD Ignition, the Factory ECU may not be able to distinguish when the coil fires. In most cases, the adapters will plug directly into MSD's harnesses. Obsolete Dual Ignition Tach Adapter.. Condition: New other (see details) ， Seller Notes: “This is an open obsolete dual channel tach adapter, It does not ship with the parts bag and the parts bag is no longer available. Ships as is with no warranty.” ，
