Use some heat and an air-powered hammer. It's noisy, but it works. These old frames can be heated and worked hot without much danger of losing strength, not like the alloy frames on newer vehicles.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!