Is the fuel pump in a 1987 Chevy pickup is pressurized?

No, the fuel pump in a 1987 Chevy pickup truck is not a pressurized pump in the same way as a modern, high-pressure fuel injected system. It's a low-pressure pump that delivers fuel to the carburetor or fuel injection system (depending on the specific engine). The pressure is then regulated at the carburetor or by the fuel injection system itself.