2007 Chevrolet Silverado 2500 HD Classic. 2007 GMC Sierra 1500 HD Classic. 2007 GMC Sierra 2500 HD Classic. Made to OE quality standards and performance. Direct Fit, no modification needed.Piston seal is provided by an OE Supplier. All-around welding on the spring seat. Newer Valving technology operates in stages based on the velocity of the car. High corrosion resistance and long service life. Tough, gloss black, with powder coated finish. We do not accept any labor claims.