I thought I had previously id'd my rearend as an 8.25 as it has the 10 bolts on the cover and the LBP lugs. However, it has no fill plug in the rear cover , the fill plug is a threaded bolt in the housing (passenger side) up by the U-joint. Did they make different versions of the 8.25? Spring perches are at approx. 43" and both have a 5 x 4.5" BP. The casting numbers on the bottom of the housing read:

2852905
0825

So I'm pretty sure the 0825 identifies it as the 8.25 right? I'm asking because I need a new ring and pinion and want to make sure I'm getting the right thing.

Any ideas?

I don't know about the casting numbers, but just to warn you, I have read in several places, that they did make a 10 bolt 7.25 in the early-mid 80's, but it's shape when veiwed from the rear is different than the 8.25.

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Jay

The "0825" does not identify it as an 8-1/4" rear axle. There have been a couple different 8-1/4" rear axles over the years; one type was used in pre-'66 B-bodies. I'm not aware of any 10-bolt 7-1/4" rear axles, but perhaps there were some. This article has your 2852905 casting number included in the list of numbers found on modern ('69-up) 8-1/4" rear axles, but it also incorrectly states that the 8-1/4" is under all '73-up A-bodies.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

You'll find them in post-1980 RWD vehicles the rear plate looks almost like a 9.25" cover instead of the 9-bolt cover.... It's a great way for junkyards to pull one over on the novice Mopar junkyarder...("Wow a 10 bolt out of a slant six Mirada...gotta have it...", the guy gets it home..."Hey wait a minute how come the rear plate isn't round...")

You don't see them that much anymore...


-D.Idiot

Thanks all. One of those interesting mysteries....the next time I have it up on the jacks I'll take some pictures and share the info.

I suppose to ensure I'm getting the right parts, I could disassemble the ring and pinion and id them from the part #'s? When I had the cover off they were deffinitely stamped with some, I just didn't write them down at the time...