Like many other Trailblazer owners, the fuel sending unit started to give bad readings especially right after filling the tank fully up. I decided to set a weekend to drop the tank and open up the system to replace the sending unit. Upon seeing how corroded the state of the fuel pump was in I decided to replace the whole assembly ($300). The lock ring was badly corroded as well to the pump so that had to be replaced as well.

NOTE: When disconnecting the fuel lines, try to be extra careful on getting them to release. They are designed to release if you press "IN" on them, but sometimes they have to be pried apart and backed off. But more time than not they break and need to be replaced. Dorman does make replacements so you can anticipate buying those as well.