Check the valve cover gasket along it's front edge, oil will run down onto the exhaust manifold from there. On your engine there will be a TDC sensor bolted on in front of the distributor. Both of those can leak ("O" rings) but normally will run down the end of the engine, not so much onto the exhaust. Probably have to remove the valve cover and if the gasket doesn't break or have splits/cracks in it, you will have to clean it and the head where it contacts, of oil/old sealant and reseal with gasket silicone. Getting a new gasket for that engine may be hard. There are also 4 flat gaskets that seal the spark plug tubes that will need looking at as well and resealing.