The exhaust manifold is located on the left side of the engine as you look at it from the front of the car. There can be a couple of designs for the gasket. The OEM units have a separate gasket for each header pipe, but some after market sets are one piece. Depending on the engine, there also may be a gasket between the manifold flanges and the precats. If you start the engine and listen near the mainfold and have someone rev it for you, you will hear it if it is leaking. Usually a hissing kind of sound, or if real bad a loud popping sound. Good luck..
2000 Dodge Grand Caravan SE