That really depends on how the car is used and what you want. Are you happy with the it's "off the line" performance as it was? Or do you crave a bit more pep when you hit the go fast pedal? Is this going to be driven mostly around town or do you plan on a lot of free way driving? Is this an auto or stick and how many gears?

If you want a little more pep around town, plan to only run the free way only when the moon is red and can deal with the extra RPM (so more fuel used), then go with the 3.73. It will be a good upgrade, especially from a stand still without being so steep that your filling up the tank every drive or can't hear yourself think at higher speeds.

However, if you are happy with the way it was before and don't feel you need the extra pep, stick with what you got.

Now would be the time to change it if you wanted.

 

Thank you. I guess I will stay with 3.08.
Talked with Quick Performance (they are great guys by the way) and they told me that 3.73 is very popular with people using (I guess) Nova axles.
Based on what you advise, I won't change the ratio. I will get new pinion and gear, at least that will allow me to use this smart sleeve from Ratech !
And I will be more confident than using the old parts, setting them on different relative position and end up with a noisy axle.

 

I'd go with 3.73 and with stock size tires by GM design, 3000 RPM is 60 MPH.
Install traction device and go.

 

It would be my car and as I have others, I may have considered it just for fun. But this car is not supposed to be kept for a long time so I will need to sale it and please most buyers that may want a decent town car and not a beast...