Complete replacement of all three engine mounts (left, right, and front) on a 1966 Chevrolet Corvette 327ci V8, requiring engine support and chassis access.

Warnings

Tools required

Parts

• Left engine mount assembly × 1 — Use OEM specification
• Right engine mount assembly × 1 — Use OEM specification
• Front engine mount assembly × 1 — Use OEM specification

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery cable
4. Apply penetrating oil to all visible engine mount fasteners and allow to soak
5. Raise front of vehicle and support on jack stands under frame rails
6. Remove engine air cleaner assembly for clearance
7. Inspect all three mounts to identify extent of deterioration and plan replacement sequence

Procedure

1. 1

   Install engine support system
   Position an engine support bar across the inner fenders or suspend engine from above using a chain hoist attached to a proper lifting plate or block-mounted lifting brackets (no factory lifting eyes are present on the intake of a stock 327). Adjust support to just contact engine without lifting. Verify support is secure and stable before proceeding. The engine weight should remain on the mounts at this stage.
2. 2

   Remove right side engine mount
   Working from underneath, locate the right side engine mount on the frame rail. Remove the 2 through-bolts securing the mount to the frame bracket using a 9/16" socket. Raise engine slightly with support system (approximately 1 inch) to unload the mount. Remove the bolts securing the mount bracket to the engine block (verify exact count per 1966 Corvette assembly manual) using the correct socket. Remove mount assembly from vehicle. Inspect frame mounting points for damage or distortion.
3. 3

   Install new right side engine mount
   Position new right side mount bracket onto engine block. Install the 3 mounting bolts finger-tight. Lower engine onto mount using support system to align frame through-bolt holes. Install the 2 frame through-bolts finger-tight. Torque engine block mounting bolts to specification, then torque frame through-bolts to specification. Work in a cross pattern if applicable.
4. 4

   Remove left side engine mount
   Locate the left side engine mount on the frame rail. Remove the 2 through-bolts securing the mount to the frame bracket using a 9/16" socket. Raise engine slightly with support system (approximately 1 inch) to unload the mount. Remove the bolts securing the mount bracket to the engine block (verify exact count per 1966 Corvette assembly manual) using the correct socket. Remove mount assembly from vehicle. Inspect frame mounting points for damage or distortion.
5. 5

   Install new left side engine mount
   Position new left side mount bracket onto engine block. Install the 3 mounting bolts finger-tight. Lower engine onto mount using support system to align frame through-bolt holes. Install the 2 frame through-bolts finger-tight. Torque engine block mounting bolts to specification, then torque frame through-bolts to specification. Work in a cross pattern if applicable.
6. 6

   Access front engine mount
   The 1966 Corvette uses two front engine mounts (left and right) at the front of the block plus a rear transmission mount. The 'front/third' mount is actually the rear transmission mount located at the tail of the transmission, supporting the rear of the powertrain. Working from underneath, identify the rear mount between the transmission tail housing and the frame crossmember. You may need to remove the lower radiator shroud or splash shield for better access using a 3/8" socket to remove 4 retaining screws.
7. 7

   Remove front engine mount
   Support the transmission with a floor jack and wood block. Remove the bolts securing the rear transmission mount to the frame crossmember, then remove the bolts/nuts securing the mount to the transmission tail housing. Lower or raise the transmission slightly as needed and remove the mount assembly. A pry bar may be needed to separate components.
8. 8

   Install new front engine mount
   Position new front mount between engine and crossmember. Align mount bracket with engine front cover or block and install the 2 mounting bolts finger-tight. Lower engine gradually with support system to align crossmember holes. Install the 2 crossmember bolts finger-tight. Torque engine mounting bolts to specification, then torque crossmember bolts to specification.
9. 9

   Verify engine alignment
   With all three mounts installed, carefully release engine support system tension while observing engine position. Engine should settle evenly onto all three mounts without binding or misalignment. Check clearances around fan shroud, hood, and firewall. Verify no wiring, hoses, or cables are stressed or pulled tight.
10. 10

    Final inspection and reassembly
    Inspect all mount fasteners are properly torqued. Check for any tools or parts left in engine compartment. Reinstall lower radiator shroud or splash shield if removed. Reinstall engine air cleaner assembly. Reconnect negative battery cable. Remove jack stands and lower vehicle.

Reassembly

1. All mount fasteners should be torqued to manufacturer specification in the sequence described
2. Engine should sit level with equal weight distribution across all three mounts
3. Verify all accessories, hoses, and wiring have adequate clearance after mount replacement

Verification

• Start engine and allow to idle. Engine should sit stable with minimal vibration transferred to chassis
• With engine running, observe each mount for excessive movement or separation
• Have assistant shift transmission through all gears while observing engine movement. Movement should be minimal and controlled
• Check for any new contact points between engine and chassis/body components
• Test drive vehicle and verify no abnormal vibrations or noises from engine compartment

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