Complete Sealing Solution for High-Vibration Diesel Engines Furthermore, the 4BG1T engine gasket kit serves as the ultimate insurance policy during a major engine rebuild. Because the Isuzu 4BG1 engine operates under significant thermal stress, we utilize Multi-Layer Steel (MLS) for the cylinder head gasket to provide a superior combustion seal. Therefore, replacing your old, brittle gaskets with our reinforced kit …