UMI Performance manufactures aftermarket suspension and chassis components for classic and modern muscle cars and trucks, with a particular focus on GM platforms such as Camaro, Firebird, Chevelle and C10/C15 pickups. Based in Philipsburg, Pennsylvania, the company also supports customers with kit recommendations, installation help and troubleshooting from its technical team.
Ground ForceGround Force manufactures tuned-performance suspension systems for light trucks, SUVs, crossovers, and performance muscle cars. The company says it has nearly three decades of experience, with its systems and components made at its Mount Braddock, Pennsylvania facility using materials manufactured in the USA. Its engineers work alongside original-equipment automotive manufacturers on suspension development.MOUNT BRADDOCK, PA
Spohn Performance, IncSince 1999, Spohn Performance has designed and manufactured high-performance suspension, chassis and drivetrain components for muscle cars and trucks from its 27,000-square-foot facility in Myerstown, Pennsylvania. Its skilled craftsmen also build custom parts such as control arms and chrome-moly driveshafts, with a focus on detailed fabrication and value. Spohn is a member of the SEMA Motorsports Parts Manufacturer Council.MYERSTOWN, PA
Martz ChassisSince 1970, family-owned Martz Chassis has built custom performance suspension systems and chassis for street rods, muscle cars and other enthusiast vehicles in Bedford, Pennsylvania. Founded by racing mechanic and engineer Gary Martz, the company remains under the leadership of his son Andy, carrying a generation of racing-derived chassis knowledge into custom fabrication and installation work.BEDFORD, PA
Progressive AutomotiveProgressive Automotive has been shaping the hot-rod suspension market since 1976, when it introduced its Mustang II independent front-suspension kits. From its Baltimore, Ohio shop, the company builds custom frames and rolling chassis for owners restoring classic vehicles, with a focus on preserving original contours while adding modern performance. Its early adoption of Corvette suspension technology earned an NSRA Industry Appreciation Award in 1984.BALTIMORE, OH