71 charger 489 case 3.23 gears....want to change to lower gears

[vacharger500]

Hi everyone,
I would like to change to lower gears, but I'm learning all this stuff as I go, since I'm new to mechanic work. What exactly is needed and or what exactly would need to be changed....ring and pinion only? Need to buy everything soon and want to be sure I buy everything needed. Thanks so much.

[randy73]

Is it a sure grip rearend?

If not, I would make it a sure grip and I would also replace all seals, but contact Dr Diff, he is a great guy and knows these rearends very well.

doctordiff.com

[vacharger500]

No clue if it is a sure grip....tag only says 3.23....can't find any other markings that say sure grip.

[cdr]

call dr diff & have him build a third member for you. http://www.doctordiff.com/

[AZMoparboy]

Hi, I'm not an expert, don't know anything about your car. This is just my spin on what might work for you. You will have to ask yourself just what is important to you.

I wanted to do the same thing to my car so I went looking for a 3rd member, didn't matter what case it was, just as long as it had lower gears, maybe 2.93's. Turned out I found a 741 case and gears on craigslist. The cool thing about this deal is, it cost just $50 bucks. It looked in good condition, just cleaned it up, checked it over, put a new pinion seal in it and basically set it back up the same way I got it and installed it. Swapping a 3rd member out is not a big job. If it doesn't work out I'm only out $50 bucks Just my   

[BSB67]

What does "lower gear" mean to you?  Sometime a point of confusion, just checking.

[Cooter]

Why do you need lower gears?
What trans are you running?
Are you concerned with fuel mileage?
Do you get irritated at driving at speeds in the 50-60 mph range to keep R's down with a 4speed/727 auto?
Building a third member is NOT for the novice. How bad does a howling rearend get on your nerves?