How To: Replace the thermostat on a 3.1L or 3.4L GM vehicle.

Replace the thermostat on your GM 3100 or 3400 with this great guide. The video shows how to replace the thermostat on a 3.4L GM, but it should also help you repair a 3.1L GM. A word of warning - you will also need to replace the O-ring when installing a new thermostat.