Does anybody know when Chevy started using crossmember mounts on 3-speed manual transmissions? I pulled the 3-speed out of my '55 Bel Air to make room for a 4-speed, and it's obviously not a '55 transmission cuz it has a mounting foot at the rear to sit on a crossmember that the '55 doesn't have. Just wondered about what vintage it might be. No synchro in 1st gear, so I'm guessing late 50s - early 60s. Any guesses?