Send your tank out to be rebuilt. http://www.v8buick.com/index.php?threads/1972-riviera-fuel-tank-wanted.331856/#post-2786612
thanks - had it reconditioned and sealed, worked well then started leaking from sending unit seal. I think its just tired, I'm in nj and cant find anyone to remake the tank, there were couple of guys doing it but they shut down. at this point just want to replace it for peace of mind.
thanks - at least I know i'm looking for the right part, now to just find one. I am stunned at the lack of parts for this year car