I have an interstate tank and the front studs are in poor condition and badly bent foreward. I want to straighten them, remove the stud, and install a pair of rubber muffler mounts. Is this a job better done cold or with heat? I am always very nervous about using an open flame or welding on a tank. I can wash it out and fill with CO2 or Argon during the process. The threaded boss has tipped in the bending process so it will require some careful tapping with a punch to make things level. Chances are good that a leak will form. Then I have to remove the studs. I tried double nutting one of them with no luck but I did not go for broke on the process. The threads are poor. Do not know if the studs have locktite or epoxy. Again heat may be the solution. The owner would like to preserve the paint if possible. If the worst happens I can do major surgery and cut out the threaded boss, make a flanged threaded insert and bring things back to normal...sort of. Paint will suffer. He does not want a repro tank. Anyone had to do this?