Gasket

If manifold was loose, and leaked, you will need to replace with a new gasket and torque to correct specs. DO not break off a bolt by tightening too much. The front and back bolt have water behind them, should use teflon tape on them to prevent leaks. Make sure manifold surface is flat no burn trails. Use whatever gasket you want, they all should work ok. I use the factory type with no problems, Fel Pro.