I am just about to install a new impeller in a Volvo-Penta 4.3 the instuction sheet states to use "gasket cement",I have worked on car engines ie.thermostats etc.and never used gasket cement.The gasket is foam do I need to get some cement or should I just put the gasket in and tighten down?Also does anyone know the torque for the little flat head screws for the cover?Thanks.