Industrial Injection GM Remanufactured Stock Heads For 01-04 LB7 Duramax - PDM-LB7SHThe Industrial Injection LB7 Duramax Stock Remanufactured Heads are designed to be a factory replacement. Complete ready to bolt on. Heads are first jet washed in a high pressure spray cabinet to remove oil and dirt, then glass beaded to remove carbon. Next they are checked by magnafluxing, (cast iron only) or pressure testing. They are visually inspected for defects that would make them unusable. New High Strength Alloy, Heat Treated iron based valve