The trucks I remember working on back then had a horseshoe-shaped front mounting bracket that bolted to four holes beside the crankshaft damper, with one set of rubber supports at the center. 55 through 57 passenger cars had two small brackets, with a mount on each side. The cars went to side mounts in 58, not sure when the trucks made the switch.
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!