standard original 3 speed would have a 2.94:1 first gear according to the books [regular 3 speed or Muncie OD] and in 58 an OD would have come with a 4.11 rear, I believe the Sag SM326 has a 2.85:1 low gear, not really much difference - if you have a hard time getting rolling that's not the problem, maybe the OD is malfunctioning as George says, or maybe your rear gears aren't what you think, 58 was the start of 'mileage minder' rear ratio options
Bill
