Rear end gear swap...opinions please

[Mpdlawdog]

Ok so my car has a 3.23 suregrip rear end....my buddy has a Dana with 3.74 gears also suregrip....he wants to trade me the housing and gears...I have to pull my axles anyway to do the wilwood brakes and bearings....so basically for $500 (talked him into doing the disc to drum conversion and bearings) id have a Dana with 3.73 and my brakes done....his rear end was rebuilt not that long ago...  My car is a 340 with a 4 speed....I'm afraid it will pull too many rpms for my liking....his is a 440 6 pack car...I drove it ones but not on the highway....any options/thoughts would help...thanks

[GoodysGotaCuda]

Are you looking for lower gears to begin with? If so, it's probably a good ratio. If not, then it may be too low for your liking.

Is it a real E-body Dana 60? If so, by swapping I think you'll make out like a bandit on that deal.

Keep in mind the Wildwood rear brakes are pretty sensitive to the axle offset, you may need to buy different caliper mounting brackets if you have already bought the brakes.

[Katfish]

I went from a 3.55 8.75 to a 3.73 Dana.
Not much difference around town, if your miles are mostly Hwy you'll notice it.

[HP_Cuda]

That would be a perfect ratio for a 5 speed!!!

[Mpdlawdog]

Are you looking for lower gears to begin with? If so, it's probably a good ratio. If not, then it may be too low for your liking.

Is it a real E-body Dana 60? If so, by swapping I think you'll make out like a bandit on that deal.

Keep in mind the Wildwood rear brakes are pretty sensitive to the axle offset, you may need to buy different caliper mounting brackets if you have already bought the brakes.

Yes. I was thinking about going to 3.55 anyway.....a 5 speed or adding an overdrive is in the future but not for a year or two ....it's an ebody Dana 60...he has a 71 challenger

I already have the brake kit but from what Ive heard there isn't any difference between axles i.e. They are interchangeable....is that right???  He wants the lower gears because he does a lot of highway driving...I was thinking my 340 might do better than his 440 as the rpms....I'll probably do some autocrossing for sure!  I figured it was a good set up especially if I get the 5 speed.....

[dodj]

If you want 3.73 gears its a good trade for you. But the dana is going to use up some of your HP just to turn it and you don't NEED a dana. If you want one, fine. If it were me I'd prefer to have the 8 3/4. More efficient, and you don't require the dana's strength. 
If I remember right, they weigh more than the 8 3/4 rears as well, increasing unsprung weight, not as good for auto-x.

[rUNCHARGER]

I'm confused by it all. It sounds like you are not getting the Dana axles? Dana and 8 3/4 axles are different. If your buddy wants to take a Dana 60 out of a 440+6 car, that is a bad choice for him. A 340 car is not even close to needing a Dana 60. Driveshaft lengths are different. 3.73 gears are a good choice with OD trans but you aren't there yet.

Sheldon

[Katfish]

Get the Dana and the OD!
340/3.73/518 = 2500 rpm at 80mph