Check the engine and year in the product name, or text us a photo of your setup and we'll point you to the right kit.
Every GMC tester here is a Duramax 6.6L kit, so start with your engine. LB7, LLY, LBZ, LMM and LML trucks use the Basic Kit, the Pro-Kit or the Shop Pro-Kit. The 2017 and newer L5P uses its own premium 30 PSI tester. The Basic Kit is a 30 PSI kit you fill through a Schrader valve. Choose the Pro-Kit for a 60 PSI kit with a 5 ft extension line and shut-off, or the Shop Pro-Kit for the same kit with a regulated extension line, so you can set the pressure exactly. The charge air cooler kit for Class 7 and 8 trucks is listed here too. Every kit is billet aluminum. Intercooler boots and clamps are the usual leak points on the Duramax, and a leak shows up as lost power, black smoke, higher EGTs and lower mileage. A leak test is the fastest way to track down a P0299 on these trucks.
