Fits 2P0483 Combustion Chamber Assembly Fits Caterpillar D8H D339 D342One New Aftermarket Replacement Pre Combustion Chamber Assembly Fits Caterpillar (Fits CAT) D339 D342 Engines This aftermarket replacement pre combustion chamber assembly Fits Caterpillar (Fits CAT) D339, D342, and D342C diesel engines as used in the D8H track type tractor and industrial and marine applications. The pre combustion chamber is a separate cavity in the cylinder head where fuel is ignited first; combustion gases then expand into the main