I bought a 1976 rear end out of a 442 on the tube it has 7 AA O 343 . I think it is a posi . I counted the gears there is 41 , 16 that makes it a 256 so why does this rear say 343? i think it is a 8.5 any info on this guys?

 

I gave 200$ for the rear end at a junk yard .Is this rear end a posi i can turn one side and the other side turns ?i can hold one side and it still want to turn i open it up and it has gears on each side is this a posi?

 

my first car was a 76 442, had the same rear end it it. i'm not sure about the #'s on the tube but i suspect that the 343 is a jullian date... if the tires both rotate in the same direction when you turn one its likely a posi. if you look closely you should be able to see plates behind the sidegears if it's a posi. it should also have a preload spring in between the sidegears( big S shaped hoo ha in the center of the carrier, the crosspin that secures the spider gears will pass thru it) forcing them apart.

 

No preload spring found more #1251502 gm 43 n or z 16 i hope it not a 1 wheel

 

Are you sure it's from a 76', as looking at my 77' factory manual the 7 indicates a 77' model year. AA indicates a 2.41(41:17 gear) open unit, with O being the manufacturer. 343 would be the day built that year. As mentioned, if a posi, will have a Z looking or small coil springs pressing against a clutch pack between the side(spyder) gears. For a quick check, hold the input pinion yoke while turning a wheel hub. If open, other wheel will turn opposite. If posi, nothing will turn and usually a silver lube tag on the lower cover bolt. The tube stamping doesn't mean it's still from the factory, as mine was a 2.41 open, but changed the guts to 3.73 posi years ago.

 

I could be a 77 .Do you have any pictures of a posi ? I did what you said to to hold the pinon and turned the hub and the other side wants to turn.

 

jump on randys ring & pinion and take a look at the tech section, lots of good stuff on there...

 

Just my luck, one will wonder? But I geuss I can buy a carrier for this one. Or if anbody has a used 8.5 or 8 1/2 gears for a 10 bolt please let me know. Now i have two will wonders and a 1969 12 bolt and a 10 bolt. Thank you guys for all the help/

 

You can certainly swap around some guts to get what you want, but keep in mind there's gonna be some precise dial gauge measurement work involved when doing this. The carrier section needs to be properly shimmed and pinion depth set for good teeth mesh contact. Not exactly rocket science, but more than just throwing parts together. If for some reason removing the ring gear from the carrier, you're wanting to install new bolts, as only designed to be stretched one time.