1966-1976 Corvette C2-C3 Radiator Isolator Cushion Brass or Copper Upper or Lower

1966-1976 C2-C3 Radiator Isolator Cushion Brass or Copper Upper or Lower - OEM Number(s) (3886891)

Protect Your Radiator—and Your Ride—With the Right Cushion Between the Heat and the Frame

Your Corvette’s cooling system works hard under pressure, and the Radiator Isolator Cushion helps it do that job quietly and securely. Specifically engineered for 1966–1976 Corvettes equipped with brass or copper radiators, this upper or lower isolator replaces the original GM part number 3886891 with spot-on accuracy and factory-style performance.

This essential cushion absorbs engine and road vibration, preventing damage to your radiator tanks, core, and mounting brackets. Without it? You're risking metal-on-metal contact that can lead to fatigue cracks, leaks, or worse—coolant loss and overheating.

Crafted from durable rubber, the isolator is molded to fit snugly in your factory radiator support brackets. Whether you're restoring a numbers-matching big block or refreshing your small block weekend driver, this part is a must for both longevity and originality.

Key Features:

• Fits 1966–1968 427 Upper Mount

• Fits 1969- early 1976 Upper or Lower Mounts

• Fits 1969-1976 with factory copper/brass 26" or 27" radiators

• Corvettes with brass or copper radiators

• Replaces GM Part #3886891

• Use for upper or lower radiator mounting

• Sold Individually

• Reduces vibration, prevents radiator wear and leaks

• Molded rubber construction ensures snug, OEM-style fit

• Essential for proper radiator alignment and protection

Finish & Material:

• Heavy-duty molded black rubber

Corvettes were made to run cool and look good doing it. This small but vital part keeps your radiator mounted securely and functioning flawlessly—so you can enjoy the ride without the risk.

Upgrade or replace today to protect your classic’s cooling system from costly damage. Add to cart now and keep your Corvette cool under pressure.

Note: Early 1976 Corvettes used 4 separate barcket on the top of the radiator. Late 1976 used 2 brackets.

Also known under these part numbers: (For reference only)

• 242013
• 360
• 3886891
• 609915
• 686420321927
• R400
• WS-498