rear end gear ratio ???'s

[autorat7]

Hi, I have been working on a little project recently, swapping 8 1/4 rears in my duster. The old rear end had a 2.71:1 ratio, and the one I'm putting in has a 3.21:1 ratio. Can anyone tell me how dramatic of a change I can expect to have when I start driving again? I am wondering about the response off the line especially, will I notice a big change? This new rear end came out of a 78-79 aspen wagon, and is a little wider than the old rear, but I have relocated the spring perches, and the extra space in the wheel wells will now be reduced, which, in my opinion, will make the ol' duster look a lot better. And I currently have a 3 spd behind the /6, but I have a OD 4 spd lined up for it, so these gears shouldn't hurt me on the interstate. Basically, all I am wondering about is the difference in the response off the line. Thanx!!!!!!!

[PapaBato]

I cant really answer your question, but i'm wondering the same thing. i know ill feel a change when i switch my 2.94 single trac with the 3.91 sure-grip, i'm just wondering how much the seat of the pants factor will go up.

[Ausydad]

I recently went from 2:45 to 3:21 in the 8.25 in the back of my Duster. Before I went to 62 mph before I had to get out of 1st, now I can't hit 40. Things are much different and will probably take a few days to get used to. The difference that I'm still wondering about is where my speedo is now. I think you will be happy with your change, although it won't be as dramatic as the change that Papa will go through. Enjoy it, I know you will!

[gsmopar]

2.76 to 3.23 is not that big. You'll be a little better off the line. If you're going to use that AOD then I would go a little steeper, probably a 3.55 or 3.91. Final drive on a overdrive trans is less than 1. example:

.76 x 3.91 rear end = 2.97 final drive ratio (get the picture?)

The Dakota R/T comes stock with a 3.91 rear and it does fine on the freeway.

Good luck,

Greg

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