Where is the oil pressure sending unit on a 2004 Chevy suburban 8.1l gas engine?

The oil pressure sending unit on a 2004 Chevy Suburban with the 8.1L gas engine is located on the driver's side (left side) of the engine block, near the front. It's usually a relatively small unit with one or two wires connected to it. You'll likely find it near the oil filter, but not directly on it. Because of the engine's size and configuration, precise visual identification from a description is difficult. A repair manual or online diagrams specific to the 8.1L engine in that year Suburban would be the best resource for pinpoint accuracy.