Here you go, 2" block's giving you 1" of lift.
http://www.readylift.com/products/chevy/chevy-silverado-1500/rear-block-kits/chevy-silverado-1500-1999-2013-2wd-4wd-6-lug-2-block-kit/silverado-sierra-1999-2013-2wd-4wd-6-lug-2-block-kit-chevy-gmc-2-oem-style-rear-block-kit.html