Many companies are now utilizing analyzer programs to evaluate the performance of engines. The fuel injection valve is a highly technical component requiring a complete seal. Perfect alignment must be achieved in order to accomplish this...that's why the Wesco cartridge is so useful. It utilizes two bushings, one each on the top and bottom, installed at the factory to ensure perfect alignment and provide maximum life from the valve. The Wesco Fuel Valve Cartridge System has greatly improved engine performance and reduced operating costs for the natural gas engines of today.