I would drain the tank and pull it. Then, with the tank on the ground, fill it with water and drill out the bolts. Retap to next size thread and drill out sending unit holes to match. That is the safe way. I've worked on a tank without puting water in it but you have to make sure that all the vapors from the fuel are gone. Make sure you clean out all the fileings after your done drilling. It's a pain, but maybe someone has done this an easier way and will respond. Cecil..........
