Originally Posted by Steve COSD
Check your fuses first! To remove the fuel pump out of the fuel door follow this process. If you have really nice paint you will need to protect it. First polish the paint with a high quality wax. Next remove the entire fuel door. Around the door opening use a 2 inch masking tape all around the opening. Get some of the thicker sheet plastic and make a hole in it the size of the door opening. You may want to double up on the plastic. Tape the opening in the plastic to the area you used masking tape previously but now use 2 inch wide duct tape. I would double up on the duct tape around the opening just for extra paint protection. The reason you want to polish the area first is it will help when it comes time to remove the tapes. The reason you want to use masking tape before the duct tape is it will come off easier. Now you are ready to remove the fuel pump. you will need to disconnect the fuel lines and the wires. After all the bolts have been removed the pump will come up and out with a slight turning of the pump assembly. As far as the sending unit is concerned if you have the funds now is the time to do this. Some things can wear out just by sitting around. You can test the sending unit when you have it out of the car just by connecting the wires and turning the ignition to on and moving the float arm up and down and watching the gas gauge through the rear window. Make sure to replace the filter at the bottom of the sender unit. Be sure to get one that is exactly the same. Your local Chevrolet dealer should have this part that is sometimes called a sock.
However, It is recommended that you disconnect the battery ground (negative) cable first just in case you get an electrical short or Arc when disconnecting the wiring harness. You do not want any kind of spark when removing the sending unit.
I just removed my sending unit in my 82 night before last. It is not difficult. The fuel pump is on the end of the sending unit and comes off easy. When you connect the new fuel pump make sure you don not get the wires crossed. If you do get the wires crossed my suspicion is that the pump may run backwards or may not run at all. Pay attention and mark the wires if need be.
The pumps at the dealerships are expensive. I ordered a DELCO pump and fuel sock from a place called the Last Detail in Atlanta. It is actually a fuel pump for an 84 but it is DELCO and it comes with a better wiring harness. American Corvette in Powder Springs GA has complete ( pump, sock float, filler neck and all) sending units for $225.00 You may want to check them out. The Last Detail (1-888-527-8338) American Corvette (770-943-2530)