Keep in mind that the tank is set in caulk (body sealer) to keep exhuast fumes and weather out. It will likely be stuck in place some. A floor jack with a piece of plywood to distribute the force will help break it loose, just jack it carefully and watch that you don't collapse the tank.
Here's some pics of the gas tank out with my 68 coupe, Pictures by Renee_237 - Photobucket
just go through the pics on the page and the surrounding ones.
1968 Mustang coupe, Acapulco Blue, 289 2v, C-4, Power Steering.
Hopefully a 1969 convertible or Sportsroof (non Mach or Boss) for next Mustang project
Trying to find my father's 1973 Mustang Grande he bought brand new. 3F04F126773 last known registration and title was in New Jersey, 1982.