8.25 Casting Numbers

[Map63Vette]

Okay, I'm pretty much at my wits end for this one and can barely seem to find any information online for 8.25 rear ends, so I was hoping someone out there can give my a hand. I just bought a project car which I've found is rather hard to find parts for since I don't know what cars the parts came out of. The car was originally a /6 auto but now has a 318 4 speed. From the looks of it the axle has also been swapped up to an 8.25 since it has the large bolt pattern. However, it doesn't look like any modifications have been done to make it fit (so I'm assuming it's out of an A body). I've found several casting numbers on the bottom side and a number on a tag, but no one seems to know what the extra numbers are. The main casting number is 3723599 (which I've found denotes it as a 71-76 8.25). However, I've read that this number is only for B bodies on one site and that it was also used for A bodies on another site, can anyone confirm this either way? The other number is below the previously mentioned one and is 10325 and then what looks to be an "A" in a circle next to it. Lastly, there are two tags, one with the axle ratio 2.94, and another that reads 1146. Does this second tag mean anything at all? I would really appreciate knowing what this axle is from, because it's missing the parking brake strut rod inside the drums and not having a parking brake on a 4 speed is killing me. It's also a 10 inch drum for what it's worth. I would really like to get a brake rebuild kit for it, but I never know what to tell the part store. Can anyone give me a hand?

 

[DionR]

If the spring perches haven't been moved, it's most likely from an A-Body. Measure the overall width, if it comes in around 57 1/8" from drum to drum, it is most certainly from an A-Body.

The e-brake strut should be easy, the 10" drums will swap from just about anything.

For the kit, tell them you have a '74 Duster with an 8 1/4" rear and they should be able to get you what ever you need.

 

[Map63Vette]

Well, I just found out that it has 2.5 inch wide brakes on it as well, and I thought I read elsewhere on here that no A body had those brakes with the large bolt pattern. It looks to be around 44.5" from center to center of the perches. From backing plate to backing plate is around 51, though that's admittedly not too accurate (hard to do with a tape measure and the tires on on the ground). The problem with the strut is that NO ONE seems to offer them new. I found Motormite to be the only company that even mentions them, but they have no Chrysler listings anymore aside from 9" Jeep drums.

 

[Demon 408]

Yes, some A Bodies, 73 and after, came with large bolt pattern and...

My response to your other thread, same subject...

73 and later A Bodies with 8 1/4 and some 7 1/4 rears (cars with disc brakes in front) came with 10 X 2.5 brakes on the rear.

Good luck with your project.

 

[Map63Vette]

Yeah, sorry about the more or less double post. I would like to know what the axle is out of so I could finally tell the part store something, but the parking brake strut is really the root of my problem. The extra tag and castings numbers were more a curiosity since I can't seem to find any info on them anywhere and didn't know if that would help me out any.

 

[DionR]

It looks to be around 44.5" from center to center of the perches.

Doesn't sound right, should have been 43" center to center. 44.5" would require moving the springs out, which would be a lot of work, or spreading them and I don't think they would go that wide.

Need to jack it up and get the wheels off to get an overall measurement. Need a friend to help hold a straight edge on one side so you can get a somewhat accurate number. Wont know for certain without getting your hands dirty.

 

[Map63Vette]

I'll have to try dropping some plumb bobs or something to get some better numbers for you. I think I'll probably end up keeping the axle since it's really not that bad of a piece with the big bolt pattern and big brakes already on it. I'll need posi and a new ratio though...