You would go towards 3. However, there really aren't any option with the original Eaton rearend. The only factory ratios were 3.90 (standard), with 4.11 and 3.38 as options. At this time, only 3.38 is available as replacement gears. Most of the vendors carry this gearset, plus
Patrick's carries them as well. Another option that may save you some money over changing the gearset would be to swap to an overdrive transmission. The original style overdrive, which is the same trans as the 3 speed but with a 2 speed auxilliary trans in the tailshaft, will bolt right in with little alterations other than some wiring and adding a control cable for the lockout. These transmission are fairly easy to find, and can usually be had for under $200. I did this swap on my '55, which has the same gears as yours, I can cruise the highway at 75 mph and only turn 2400 rpm. I do admit to having bigger than stock tires, which cuts the rpm down as well. It's a very enjoyable transmission to drive, very flexible, as it essentially gives you 6 forward gears and can be used as a gear splitter just like the big trucks.
