Performance Online offers you a wide variety of options when considering what you want to do with your classic 1947-55 Chevy and GMC 3100 truck. Our leaf springs are 5160 spring steel and maintain the factory GVW and are available in stock height or 2.5" lowered heights. Leaf springs meet or exceed the factory specifications. Lowered springs come standard with reversed spring eyes. Slight modifications are required during installation.