Commando

Anyone know the part number for the 9 1/4 rear in a B-Body? I have been looking for awhile online and can't find any info. Before I go out and start looking at scrap yards I want to have an idea what to be looking for besides the 12 bolts.

Also to confirm that an open diff turns the wheels in different directions, and a posi turns the same way, or am I reversed?

Commando

Ok, I wasn't sure on the history or anything, if I use the axle dimension chart and look up for b-body it is the same specs as what I got, but for years it says all.

67 GTX

if it is a posi, both wheels will turn in the same direction when one is turned

78D200

If the posi unit is worn out though, it will act as an open carrier unit. Your best bet is to pull the cover off and look inside. Of course if you find one where both wheels turn in the same direction, you son't have to pull the cover.

Commando

Thanks, I think I would rather find one that has them spinning in the same direction, unless the the whole unit is in good shape.

Commando

Please someone tell me that a 73 coronet is a B-body. If so I think I have found what I am looking for.

Polaradude

Why, yes it is my friend.

Commando

Awesome, now I just need to figure out in the pics why it doesn't look like the other 9 1/4 with the stop sign look, or is that just for the later ones found in trucks?

78D200

post up the pic if you can. I think that stop sign look is just on the Rams, Dakotas, and Durangos.

Commando

78D200

The axle tubes look big enough for it to be a 9 1/4, just not too sure about it from the look of the housing.

Can the seller send you any pics of any tags or numbers on it?

Its very clean.

Polaradude

There should be a " bill of materials " number on the axle tubes.

Commando

I am going to take a look at on Thursday, I found three part numbers that were stamped on them: 3507890, 3507891, and 3723199. If anyone knows of any of the others for a 1973 please let me know.

Commando

It was a stock option in the Cordoba, and it will bolt right in. I don't think the 8 1/4 I have in there will hold up to the estimated 500+ ft lbs of torque.

78D200

HAHAHAHAHAHAHAHAHAHAHAHAHAHA

I wouldn't trust an 8 1/4 with over 250 torque.

Commando

My mechanic who has recently changed roles to an adviser, (not sure if he is aware that he isn't going to get any work from me that I can do myself,) said that I needed to change it. Of course I believe him, he has more experience then anyone I know, but there is the same Chevy guy I have referred to before said I should be fine. In the same sentence he will tell me the way it needs to get done, and that he has no clue on how the mopars work. He said let it break, and I always reply I prefer not to break anything while driving, especially something like that which could be potentially dangerous, or expensive if it breaks in the wrong place.

crmzendrgone

if you still need it i think i can get a hand on a parts book at my work for that year and look up the numbers

Polaradude

Ya thats why all the Cheby guys run Ferd 9" rears....mmm, lets think about that shall we. Never trust a Cheby guy, they don't even trust they're own parts.

Commando

Nice, If you could check the numbers I would appreciate it, as I don't want to make the mistake I made last week and rely too much on the person selling.

Are there any numbers other then those three that fit the b-body?

crmzendrgone

I looked up the axle for 78 passenger cars out of our books, we have a lot dating back to the fifties. Anyway the 78 parts book has the part number listed for a 9 1/4 as 3507702. That is the housing package, I can find other numbers just let me know.

Commando

That wasn't even on the list of numbers, 3507890, 3507891, and 3723199.

crmzendrgone

I saw that but that is what the book has for it. What year did those numbers come off of? and what year are you looking for maybe i looked at the wrong one.

Commando

Not sure what years they are from, just what I found when searching online. Preferably a 1977 rear, but I will take any that came off a b-body as I read from the rear diagram, that all of them are the same.

crmzendrgone

So I looked up the numbers in the 1977 parts book (for some reason i thought you wanted a 78) and the numbers that you have are for the 1977 b body vehicles. It has a note in the book that the 9 1/4's will have those numbers stamped on the axle.

Commando

Ok cool, I just randomly found those numbers online and had no year to associate them with. Thanks.

crmzendrgone

Your welcome, finally i feel like i have helped someone. I was starting to think i was useless. hahahahaha

I read back on this thread a few post ago that you wanted part numbers for a 1973 do you want the part numbers for a 1973 axle i can try to look for them. I am sure we have that book to?

Commando

It turns out the 73 was an 8 1/4.

But if you have the numbers I would appreciate them all through 77 as I will be looking for anyone of them.