SO I WANNA SWAO OUT THE TORQUE TUBE ON MY 53 1/2 TON BURB AND FOUND A GUY WITH WHAT IM ASSUMING ARE A 318 AND A 319 ( HE SAID HE HAS 2 55-57 3 SPEEDS, ONE WITH O.D. THE OTHER WITHOUT) ARE THE GEARS INTERCHANGEABLE, I MEAN I WANNA GET AND USE THE O.D. TRANS, SHOULD I GET THE OTHER 3SPEED FOR PARTS? THANKS