Spring Sleeve 4.25 Discontinued

The Spring Sleeve 4.25 Discontinued is a precision-engineered upper spring cup assembly designed for high-performance automotive and mechanical applications requiring controlled spring compression and load management. Built by ALLSTAR PERFORMANCE—a trusted name in motorsports and industrial engineering—this bolt-on sleeve delivers the durability and repeatability demanded by fabricators, mechanics, and serious enthusiasts who depend on stock standardization and long-term component reliability in demanding environments.

Manufactured from steel with cadmium plating, the Spring Sleeve 4.25 features a 4.25-inch inner diameter and is part of ALLSTAR PERFORMANCE's Pro Series spring cup lineup. The cadmium finish provides superior corrosion resistance and wear protection, critical for components exposed to moisture, salt, and thermal cycling. The bolt-on design eliminates welding and custom fabrication, allowing for straightforward installation, adjustment, and replacement without compromising structural integrity or requiring specialized equipment or training.

This upper spring cup sleeve is ideal for shop environments, racing operations, suspension assembly, and restoration projects where OEM-equivalent or aftermarket spring packages must mate with industry-standard mounting points. The Pro Series designation indicates compatibility with standard spring assembly protocols and fastening methods. At 0.53 lbs and compact 5.55 x 2.1 x 9.15-inch dimensions, the sleeve is easy to stock, transport, and integrate into existing systems—making it a reliable replacement for discontinued original equipment.