Gear ratios

[Fern]

Hi,
The rear axle that came in my car had spun a bearing at some point and someone fixed it by placing a metal sleve, needless to say its junk. Since I need a new rear, I was going to go with 355 sure grip, but I have found one thats a 323.
My question is is there much difference from one to the other?  I am looking for something I can drive in town and on the highway, but dont want it to be sluggish from takeoff.
I have 70 challenger with 440 4 speed.
Thanks,

[dutch]

I don`t think you will have sluggish take off with either one... with a 440 -4 sp.   
this may help visualizing things...

http://vexer.com/automotive-tools/speed-rpm-calculator

[Jocigar]

Guess I won't be going of the highway with 4:10 gears  3500rpm would not be fun on long trip.

[dutch]

Guess I won't be going of the highway with 4:10 gears  3500rpm would not be fun on long trip.

same here.... but tons of fun the rest of the time 

[MEK-Dangerfield]

If you have a 440 4-speed, no problem going with 3:23.

You can still chirp the tires at red lights, and you can drive all day on the highway.

Do you have any engine upgrades from a stock engine?

[PlumCraZRT]

It's probably worth mentioning that I used to have a 3.23 rear with 235/60R15 tires.  I switched the rear to a 3.55 unit when I had the rear rebuilt, but I also switched to 275/60R15 tires.

Between the height change on the tires and the change in ratio, the freeway RPM is the about the same (~2% difference).  Something to think about if you have a specific tire in mind or not.

[Fern]

Great advice
Thanks
by the way its a stock 440 with 906 heads