Large Spring Isolators

High-Performance NVH Suppression for Full-Size Ford & GM Tubular Control Arms

Upgrade your classic’s ride quality with Fatman Fabrications’ specialized spring isolators. Unlike standard rubber or soft urethane, these isolators are injection-molded from genuine Delrin® plastic, engineered to fit perfectly within the heavy-duty lower spring cups of our GM Control Arms and Full-Size Ford Control Arms.

The Delrin® Advantage

Delrin is a high-performance acetal homopolymer known for its exceptional stiffness, low friction, and dimensional stability.¹ In suspension applications, Delrin is superior because:

• High Load Bearing: It does not "mush" or compress under the weight of a heavy engine, maintaining your ride height and alignment geometry.

• Self-Lubricating: It provides a low-friction surface that allows the spring to pivot slightly without the "binding" or squeaking common with rubber.²

• Indestructible Performance: It is highly resistant to moisture, road chemicals, and extreme temperatures, ensuring it won't crack or rot over time.³

Precision Fit & Dimensions

These isolators are designed to interface seamlessly between your coil springs and the 3/16-inch thick stamped steel spring cups of Fatman Fabrications lower control arms.

• Inside Diameter (ID): 3.25"

• Outside Diameter (OD): 5.125" (5 1/8")

• 1.5" Tall

• Spring Compatibility: Specifically sized to fit coil springs with a 5 1/8" ID, common in full-size Ford (1957–1964) and GM (Chevelle, Impala, etc.) performance applications.

Technical Summary