Can the silver emission pipes on a 305 engine be taken off of exhaust manifold and holes plugged?

The silver emission pipes on a 305 engine, also known as heat riser tubes, can be removed and the holes plugged. They are part of the emissions control system and are not necessary for the engine to run.

To remove the heat riser tubes, you will need to:

1. Disconnect the exhaust manifold from the exhaust pipe.

2. Remove the bolts that hold the heat riser tubes to the exhaust manifold.

3. Carefully pry the heat riser tubes off of the exhaust manifold.

4. Plug the holes in the exhaust manifold with the appropriate sized pipe plugs.

Once the heat riser tubes are removed and the holes are plugged, you can reinstall the exhaust manifold and exhaust pipe.

It is important to note that removing the heat riser tubes may affect the emissions performance of your vehicle. If you are concerned about this, you should consult with a qualified mechanic before removing the heat riser tubes.