Cusco 684 421 A60 Non-Adjustable Rear Pillowball Upper Mount Set

The Cusco 684 421 A60 is a non-adjustable rear pillowball upper mount designed to replace the factory rubber strut mount with a solid, high-performance alternative. By eliminating the compliance of the OEM rubber mount, this pillowball unit delivers direct road surface feedback to the driver while keeping alignment geometry locked at its static position during hard cornering, acceleration, and braking.

Constructed from 6mm thick 2017S duralumin plate, these mounts offer exceptional rigidity and durability without excessive weight. The solid pillowball assembly replaces the flex-prone factory rubber, ensuring improved steering response and consistent handling performance — especially when paired with coilover suspension upgrades.

Key Features:

• Non-adjustable (fixed) pillowball design for consistent, reliable alignment geometry
• 6mm thick plate manufactured from lightweight 2017S duralumin
• Improves steering response and high-speed cornering stability
• Maintains static alignment settings under hard braking and acceleration
• Requires spring inner diameter (I.D.) of 60mm or smaller

Cusco is a Japanese aftermarket manufacturer with deep roots in motorsports, including rally, time attack, and circuit racing. Their pillowball upper mounts are a popular upgrade for performance and track-oriented builds seeking more precise suspension response than factory rubber mounts can provide.