GM trucks equipped with the L5P diesel are a modern marvel of engineering and design. They're a winning combination: a powerful workhorse, with low emissions, and great styling. Unfortunately, they have been outfitted with undersized, restrictive stock up-pipes. Now you can upgrade the L5P to achieve higher-flow by bolting on PPE OEM-Length Replacement High-Flow Up-Pipes. These direct replacements have a 46% larger flow area over stock, which results in a deeper-breathing power-plant, while maintaining the mandated Federal emissions standards of stock. The PPE OEM-Length Up-Pipes are manufactured from 11 gauge 304 stainless steel. These new Up-Pipes include the superior PPE internally-sleeved bellows, also manufactured from 304 stainless steel. This system is engineered to take the abuse of high temperatures and high pressures, while promoting increased exhaust flow and lower EGTs. A superior product for your modern marvel.