Hey Guys,
I want to get new rear gears for my '77 this summer. You can see what I have aside from stock in my profile. I believe its got 3.08 in the rear now. I was looking at Jegs and I'm not sure what the rear end is... I'm thinking 10 bolt, but is it the 8.2". I just don't know if I'm looking under the right section. I was also wondering which set you guys think I should go with.. this summer I will be adding headers, a cam, and possibly some work on the heads (depends on funds). I was thinking 3.55???

Bob Herman (aka bherman) told me of a place in southern Wisconsin that rebuilds differentials. It doesn't matter to them if they put back your original gears or swap to any ratio other ratio you want - same price. If he doesn't respond to this thread in a few days I'll rattle his cage for the web site, phone number, whatever and get it posted here.

Thanks for the info, but I'm going to try to do the change myself. I want to learn all the good stuff and the only way to do that, is to try it myself. I have very good help if I need it.... that's why I'm not scared to take it on myself.

It would be very interesting if you took some pics as you do the job and post them for those of us who have never done the job and can not afford " good help ". I actually toyed with the idea of replacing the whole differential cause on the surface it seems easy enough that even I could not screw it up, well, I'll take that back. I could screw it up. I am running 3.08 now and am thinking about maybe 3.73 or even 4.11 but I want to have a simple job so I can switch it back and forth in a couple hours.
Good luck to ya and let us know how it goes.

Bob (bherman) has some pretty short gears in his BB '68 he's looking to replace. "Pulling to many R's while cruzin' down the road builds up too much heat" is one reason he gave me for wanting to make the switch. Drop him a note and see if a swap would work.


Jim O.

Glenn
I think there is a difference in the carrier for 3.73 and 4.11.
2.something up to 3.73 has one kind carrier and everything above a different one.
Can't remember wich one is a -3 or -4 unit.
I did hear that a spacer can be installed , but it's not recommended.
Hope somebody with more knowledge on this jumps in.
Gunther

Hopefully someone will jump in before both of us make a big mistake. I always thought the rear casings were all the same size. Anyone know for sure?

The 4.11 gears take a series 4 positraction carrier and any gear ratio less than that takes a series 3 carrier. The external housing (the differential pumpkin) is the same. Unless you are very good I would suggest that differentials be set up by someone with the proper tools AND experience. Too many ways to go wrong here.

Call a friend of mine named Harvey Jacobs at 412-264-9151 and he can set you up with a complete rebuild. He did the differential on my 66 and my 72. If you decide to do this yourself, he can still get you the gears.
Gary

Gary,

Please say "Hello" to Harvey for me the next time you talk to him. He may not remember me, but he helped me out a couple of years ago when I was looking for someone to do a pre-purchase inspection on the car I eventually bought. Thanks!


Jim O.

|UPDATED|5/2/02 1:14:37 AM|/UPDATED|

Thanks, Gary !