Gears

[69383RR]

Yep , great forum , love it !:cheers:

 

[Basketcase]

here's a sweet rear end....

 

[69383RR]

The 69 rr has one of the nicest rear ends of any car out there . Simple , clean and sexy ,even in primer !

 

[ACME A12]

I also have 4:56 gears installed presently and I'm thinking about replacing with 3:91's. Bad part about it trying to find someone local that has enough experience with the 489 case.

Hey Jeff, I know a guy in Plant City that is really good w/ the 489s. He's a Tampa Fireman and builds differentials on the side. He rebuilt a cone SG unit for me for the Swinger a few years ago. Reasonable $$ too. Let me know if you need his services. He might even have a chunk w/ 3.91s ready to go on the shelf so you can keep both ratios.

 

[gunnar]

here's a sweet rear end....

Yes, beautiful. Reminds me of my old runner.

 

[4spd69RR]

Hey Jeff, I know a guy in Plant City that is really good w/ the 489s. He's a Tampa Fireman and builds differentials on the side. He rebuilt a cone SG unit for me for the Swinger a few years ago. Reasonable $$ too. Let me know if you need his services. He might even have a chunk w/ 3.91s ready to go on the shelf so you can keep both ratios.

Good news, wonder if he would like to trade dif for dif? What do you think. If he is not interested in trading I do have another Dif with 2:72 installed that can be swapped out. You say he's good. Everyone I talk with does not want to tough the 489 housing because of the crushed sleeve.

 

[ACME A12]

Good news, wonder if he would like to trade dif for dif? What do you think.

I have no idea on that...you'd have to address w/ him...

 

[4spd69RR]

If he is not interested in trading I do have another Dif with 2:72 installed that can be swapped out. You say he's good. Everyone I talk with does not want to tough the 489 housing because of the crushed sleeve. PM me his number and I will check.

 

[ACME A12]

If he is not interested in trading I do have another Dif with 2:72 installed that can be swapped out. You say he's good. Everyone I talk with does not want to tough the 489 housing because of the crushed sleeve. PM me his number and I will check.

The crush sleeve is not the issue that trips most people up; it's the cones in the SG. Not a serviceable item - but a little backyard magic works wonders.

I called him & left a message to see if he's still doing them. I'll send you a PM as soon as I hear back from him.

 

[4spd69RR]

The crush sleeve is not the issue that trips most people up; it's the cones in the SG. Not a serviceable item - but a little backyard magic works wonders.

I called him & left a message to see if he's still doing them. I'll send you a PM as soon as I hear back from him.

Roger that, and thanks!

 

[red 69 runner]

My car has 323 SG ,when I put 15" wheels on it with taller 275/60 tires it feels like it dosent have the balls it used to with the smaller 14" smaller tires.I am going to replace the 323 with a 391 but everybody I talk to says I dont want to go that high for driving on the highway,I am at 2000 at 60mph now.I used a calculater I found on a web site and it should only bring the rpms up about 200 more.I can live with that.I have a buddy with 456s and he is at 4000 rpm going down the highway,definatly dont want that.

 

[4spd69RR]

If you are worried about the RPMs, why not look into 3:55 or 3:73. If you plan on doing a lot of highway driving you might not want 3:91 gearing.

 

[pinkpanthr]

My car has 323 SG ,when I put 15" wheels on it with taller 275/60 tires it feels like it dosent have the balls it used to with the smaller 14" smaller tires.I am going to replace the 323 with a 391 but everybody I talk to says I dont want to go that high for driving on the highway,I am at 2000 at 60mph now.I used a calculater I found on a web site and it should only bring the rpms up about 200 more.I can live with that.I have a buddy with 456s and he is at 4000 rpm going down the highway,definatly dont want that.

Don't know if you're running an auto or 4 speed, so I'm gonna assume 4 speed. You're 4th gear in a stock 4-speed is basically 1:1 ratio. So with 3.23 at 60 you should be at about 2250 with the wheel/tire combo you described. Switching to 3.91's will probably move you up to somewhere close to 2800 at 60 if you're at around 2 grand now. That means that at interstate speed you'd be close to 3300 (70mph) 3.55s would put it around 2500 at 60 and 3000 at 70mph. Droptop has a pinion spreadsheet that shows all of this, but its set up for automatics so you have to adjust it a little.

 

[red 69 runner]

Its an automatic,I am just going by the tag on the rear ,not sure if the gears are 323, have to jack it up and count the drive shaft turns,maybe not 323.not worried about rpms as long as they are not over 3000

 

[Basketcase]

I hve 15" on mine, with the 275s on the back, has plenty of balls...at least from what I remember....

 

[mcmopar]

Love my 3.55 Sure Grip. Nice all-around gear.

 

[Roadcuda]

I was talking to a guy tonight about having rear ends rebuilt. To have it done, what would be a good average price for a rebuild and reusing the pinion and ring gear.

 

[4spd69RR]

I would not have a good price to suggest, every time I ask about rebuilding and installing new gearing into my 489 housing, I am told to find someone else that can rebuild 489's.

 

[Roof man]

I was told $1200.00 all in to change mine to 3:55

 

[Roadcuda]

I was told $1200.00 all in to change mine to 3:55

Dr Diff is selling them for that! And I've heard a lot of good things about his work.