First of all, congrats on your car, those `61 Starliners are just terrific looking beauties.  Before sharing on the rear end, assume your car is a 352 or 390, but curious, is the close ratio a Borg Warner T-10 or Toploader? 

So here's my opinion.  For these heavy Galaxies, part of the answer to your question lies in finding the right starting line ratio (SLR).  As you may already know, SLR is calculated simply by multiplying the rear-end gear ratio by the first gear ratio.  It's also a good way to look at how the gearing will work on the car.  

Let's say a Galaxie has 3.50 rear gears and a 2.78-1 first gear.  To find the SLR, you multiply 3.50 x 2.78 which is 9.73-1.  While racing enthusiasts may also consider stroke and weight when finding the right SLR, generally the rule of thumb for cars in the 4000lb weight class like our Galaxie's is an SLR in the mid-8s or higher.  

The further below 8.00-1 the SLR, the more the car will feel like a dog off the line.  That's because it'll be "under-geared".  Now granted you're not going to be taking your car to the track, still you want to keep some balance between good launch characteristics and comfortable cruise speed.  

To have a good cruise speed, the motor is turning around 2,500 RPMs while the driving speed around 65-70mph.  

Whether your Starliner has a T-10 (2.36 1st gear) or Toploader (2.32), for a car that won't see the track and instead will be driven on the street and perhaps cruising on the highway too, a good choice would be 3.50 rear gears.  That way, your SLR would be around 8.25, giving you somewhat reasonable off-the-line launch feel and decent cruise speed too.  

If you'll be cruising more on the highway and that's more important to you, you could always go with 3.25 rear end. Your SLR will be around 7.65 and you'll have higher cruise, but the car will feel a bit more sluggish off the line.  Overall, the higher you go with the gears (i.e. 3.00, 2.80, etc), the worse the car will feel off the line ... and the higher the cruise.  

Conversely, if you dropped to 3.70 gears, your SLR will increase to around 8.7 and the car will feel better off the line.  But your cruise speed will drop.  I think you get the idea.  

To give you some frame of reference, my Galaxie is setup with 3.50 gears and a wide-ratio Toploader with a 2.78 1st gear.  The starting line ratio is 9.73-1 and the car feels great off the line.  Yet I can cruise at around 70 mph turning 2,500 RPMs.  To me, that's the perfect balance and exactly what I wanted.

Hope that helps.