Were is the oil sending unit on a 97 Chevy Tahoe with 5.7 engine?

On a 1997 Chevy Tahoe with a 5.7L engine, the oil pressure sending unit is located on the driver's side (left side) of the engine block, near the oil filter. It's a relatively small unit, often with a single wire connected to it. You'll likely need to look closely and possibly use a flashlight to spot it. It's usually near the bottom-front of the engine, but its exact position can vary slightly depending on the specific engine configuration.