What way does the thermostat go in on a 1994 Chevy silverado 1500 5-7L.?

The thermostat for a 1994 Chevy Silverado 1500 5.7L goes in only one way. It's designed with a specific orientation to ensure proper sealing and coolant flow. There are usually protrusions or a specific shape on the thermostat itself that dictates its placement.

You cannot simply guess. The best way to ensure correct installation is to:

1. Refer to a repair manual: A Haynes or Chilton manual specific to your year and engine will show a diagram and describe the proper installation. This is the most reliable method.

2. Examine the old thermostat: Before removing the old thermostat, carefully note its orientation in the housing. Take a picture if needed.

3. Look for markings: The thermostat itself or the housing may have markings indicating the correct orientation (though this isn't always the case).

Installing the thermostat incorrectly can lead to poor engine cooling, overheating, and serious engine damage. If you're uncertain, seeking professional help from a mechanic is recommended.