Where is the oil sending unit on a 1982 350 Chevy silverado?

On a 1982 350 Chevy Silverado, the oil pressure sending unit is located on the driver's side (left side) of the engine block, near the distributor. It's a relatively small unit with one or two wires connected to it. It's usually close to the oil filter, but not directly on it. You'll likely need to look carefully around that area to locate it. It might be a bit difficult to see depending on accessories attached to the engine.