This week I had to drop the tank out of my '88 GTA since the fuel pump was dead. The car had sat 7 years and it has some gas left in it. I siphoned out about a gallon or so. The pickup has rust on it and the tank has some debris in it. I figure the pickup could clean up decently but I'm not sure which direction to go with regarding the tank itself. My options are leaving it as is and dumping in new gas, trying to clean the tank out with a variety of methods, or replacing the tank, either with a clean used one or a brand new tank. There is some larger debris which seems to be parts of the black rubber boot which was around the fuel pump itself. It basically melted/disintegrated. I'm not sure how much of it I can get out. Also, there is what seems too be like small granular debris, gray and black, almost like tiny gravel/grit particles. The old gas seems like it crystallized and left little formations on the bottom of the tank.
Has anyone here cleaned an old tank like this? If so, what method worked best? Will rust come back and should I just go for a new one right away?
I don't want to get it all back together and have issues in the future since dropping the tank isn't a 15 minute job.
A new Dorman tank is about 155, a SPECTRE tank is about 150. Both at rockauto.
Here are some pictures..