Where is the fuel regulator on a 2000 Cheve Blazer 4.3L?

The fuel pressure regulator on a 2000 Chevy Blazer with the 4.3L engine is integrated into the fuel rail. It's not a separate, easily identifiable component like on some older vehicles. You'll find it on the fuel rail itself, usually near the end furthest from the engine. To access it, you'll likely need to remove some components from the fuel rail.