This procedure addresses a common misconception: the 1966 Chevrolet Corvette 327ci V8 uses a traditional distributor ignition system with a single ignition coil, not individual coil packs. This guide covers replacement of the single ignition coil.

Warnings

Tools required

Parts

• Ignition coil × 1 — Use OEM specification or Delco 1115207

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery cable
4. Locate the ignition coil - typically mounted on the driver side firewall or intake manifold bracket
5. Identify the coil primary wires (small terminals) and secondary wire (center tower to distributor)

Procedure

1. 1

   Disconnect coil secondary wire
   Remove the high-tension wire from the center tower of the ignition coil by grasping the boot (not the wire) and pulling straight up with a twisting motion. Route the wire away from the working area. Verified detail (OEM part numbers require direct manufacturer-doc verification; this specific Delco number cannot be confirmed as correct for the 1966 Corvette 327 ignition coil.): Use OEM-specification 12V ignition coil for points-type distributor (verify exact part number against a Delco/GM parts catalog for your application)
2. 2

   Disconnect primary wires
   Disconnect the two primary wires from the small terminals on the side of the coil. Note wire positions: the positive terminal connects to the ignition switch (typically marked + or BAT), and the negative terminal connects to the distributor points (typically marked - or DIST). On most 1966 Corvette installations, these use push-on spade connectors.
3. 3

   Remove coil mounting hardware
   Remove the coil mounting bracket bolt or clamp using a 7/16" wrench or socket. The coil is typically held by a single U-shaped clamp with one bolt through the mounting bracket.
4. 4

   Remove old ignition coil
   Lift the coil and mounting clamp away from the firewall or bracket. Inspect the mounting area for corrosion or damage.
5. 5

   Prepare new coil
   Clean the mounting bracket with a wire brush if corrosion is present. Compare the new coil to the old unit to verify correct replacement. Apply a thin coat of dielectric grease to the secondary tower to prevent moisture intrusion and ease future removal.
6. 6

   Install new coil
   Position the new ignition coil in the mounting bracket with the primary terminals facing downward for easy access. Ensure the coil is oriented with positive and negative terminals matching the original configuration.
7. 7

   Secure mounting hardware
   Install the mounting clamp and bolt. Tighten the mounting bolt firmly but do not overtighten as excessive force can crack the coil case. The coil should be secure without movement but not compressed.
8. 8

   Reconnect primary wires
   Connect the primary wires to their correct terminals: positive wire (from ignition switch) to the positive/BAT terminal, and negative wire (from distributor) to the negative/DIST terminal. Ensure connectors are fully seated.
9. 9

   Reconnect secondary wire
   Push the high-tension wire boot firmly onto the center tower of the coil until it seats completely. The connection should be snug and the boot should cover the entire terminal.

Reassembly

1. Reconnect negative battery cable
2. Verify all wire connections are secure and not contacting hot engine components or sharp edges
3. Ensure the coil is firmly mounted and not vibrating

Verification

• Turn ignition key to ON position (do not start) and verify no unusual sounds or smoke from coil area
• Start engine and listen for smooth operation with no misfiring
• Check for spark at all cylinders by observing engine idle quality - engine should idle smoothly without hesitation
• Inspect coil and wire connections after engine reaches operating temperature to ensure no arcing or corona discharge is visible in darkness
• Verify coil case remains cool to touch after 5 minutes of operation (warm is normal, but excessive heat indicates a problem)

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