A little rear confusion.

[Dad's74RR]

Hey I got a little more reading done on my 408 stuff so I think I'm good there but I'm still stuck on my rear end situation. My Satellite has a factory 2.62 rear gear and it's just not going to fly for me. I want to install 3.55 and I think I would be happy with that. I also want to "lock" the rearend so I'm not spinning one tire. How do I id my current parts so I know what new parts to order? Any help would be great. Thanks!

 

[Meep-Meep]

Going from 2.? to 3.55 may require a carrier change, but that's on the agenda anyway since you want to go with a sure grip (locking rear end).

Are you trying to ID the axle assy? If so here are some things to look for. The popular 8-3/4 has a drop out center section and no bolt on rear cover. The 8-1/4 has a bolt on rear cover that's kind of oval shaped. 9-1/4 has a bolt on rear end cover that's sort of stop sign shaped (I doubt you have one of those). Hope this helps.

 

[72Satellite440]

I think you were looking at the gear ratio stamp plate of 2.71- in a 8 1/4 rear-
Definitly go with a 8 3/4 or "dana" 9 1/4-
*Be make sure to get the correct body size there are a few different wheelbases*
8 3/4 in the black and 8 1/4 on the bottom


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[Dad's74RR]

Ok that should really help. I actually get to bring it to my garage today. I'll look over the assembly and compare it to what you have said. And the picture of course. I'm almost sure it's a 8 3/4. But I'll find out today. Is the 8 3/4 significantly stronger or more durable that the 8 1/4? I've done reading on the 8 3/4 and know it's good.

 

[Cranky]

Yes, the 8 3/4 is stronger than the 8 1/4 and if this is a street car, you really don't want a locked rear end. What you do want is a limited slip rear, ie a SureGrip in Mopar term. Positrac in GM's term....

 

[1badgtx]

I had a 2.0 gear in my gtx when I got it...It did have the suregrip posi unit...I called up a buddy that had an extra set of used gears laying around..It was a 3.55 gear set...This really woke up the car...You can get a new gear set for about 200 bucks...New bearings and shims for the carrier are about the same in price...You should also take a close look at your axles while they are out...My car was an ex drag car at one time and one of my axles was twisted at the splines like a candy cane!!!I bought a set of chromeoly axles for 250 bucks.They are alot stronger than The stock ones...Unless you are running 500+ hp your 8 3/4 will hold up just fine..
Petty Blue 67 GTX

 

[Cranky]

2.0 gears?

 

[1badgtx]

1.97 I think...This was 3 years ago..It was a crazy tall *** gear...I,look have to look for it to be sure..Might have tossed them..I knew they just had to go....
Petty Blue 67 GTX

 

[Cranky]

If this was an 8 3/4, the tallest gear available was a 2.76, then a 2.94 with the 3.23 being next, 3.55, 3.73 (in earlier units), 3.91, 4.10.....and so on.

 

[Dad's74RR]

Ok, it's definitely an 8.25 so that's kind of a bummer. I know where a satellite is with a roadrunner hood so maybe I'll just buy it and take the 8.75 out of it. It's sitting in junk yard and I could pick it up cheap. It also has a 400 engine in it so I may be able to recoup some of the money that way. On the sure grip-- will it allow both tires to spin when I get on it or will only the left one spin? I don't want to leave one black mark. It looks too funny.

 

[1badgtx]

It,s a 2.76...Now I need to to toss it away...Too many parts not enough storage space...
Petty Blue 67 GTX

 

[Cranky]

Someone might want it instead of tossing it. What case is it? I used to run a 2.94 in my 383 4 barrel 70 Challenger. Loafing speeds around 60 and cruising was easy at 85. I would have used a 2.76 had I had one. I used to do some hi-way traveling and my Challenger was my cruiser. My dad used to live 150 miles away and gettng there in just under 2 hours was pretty easy....

 

[Meep-Meep]

I did some work on an 8 1/4 and I have to say I wasn't terribly disappointed. The carrier bearings are the same as the 8 3/4 and I think the pinion bearings might have been the same also. An 8 3/4 install would be a no brainer decision but it would be interesting to know if anyone has successfully ran an 8 1/4 behind a hot street engine. Based on supply and demand alone I'm sure they are not cheaper to build than an 8 3/4 - me thinks - but the good news is they are usually free.

 

[Cranky]

The 8 1/4 isn't bad but it won't take the punishment like the 8 3/4 will...

 

[YY1]

I've seen a couple sure grip units for 8 1/4 axles on ebay for under $200.

Haven't seen any ring and pinions, though.

 

[Dad's74RR]

Ok, so here is what I have found. The junk car thing is kinda cool. I need the hood, want the 8.75, could sell the 400 and turns out it has a console that I didn't know about. I'm probably going to buy this whole thing(junk yard won't part it out) and strip a bunch of the good parts. I wouldnt normally do that but this car has hit a pole and definitely isn't restorable. I will actually keep the 8 1/4 in my garage if I ever decide to just do a full restoration. It's still numbers matching engine tranny too but I'm wrapping those up and hiding them. There aren't a bunch of great parts but I'll just get as many as I can before the wife kicks it out or me out. I'll post a new thread for the parts and I guess a new one when I get into the rear and find out what I have in there.:tiphat: