Help needed identifying 8.5 10-BOLT rearend,please

[thunderhead]

I bought a 8.5 10-bolt yesterday that is said to be out of a 1984 or 1985 Olds 442 with 3.73's & open carrier.I measured it before I bought it and it's the correct width for a G-body but,I did numerous searchs of the numbers off the axle tube and center section and can't find anything to identify it.I checked Olds sites,Buick sites,Googled the numbers various ways and find nothing.One thing that is making me wonder about it is,I've got a new rear disk-brake kit I want to use on it when I put
it back together.I just noticed this morning that the axle ends don't have a typical,4-bolt flange the backing-plates bolt to.
It's got a rectangle flange that has 2 small bolts at the bolt and looks like 1 large bolt,centered at the top and a cut-out to
allow for the brake-line to get to the wheel cylinder.It has 6 TFG 344 on the axle tube and 14075742 on the center section.
Can anyone help me identify this rearend,please? I drove 2 hours there and 2 hours back and I'm going to be pissed if I got
something other than what I was told it was.I know it's a 8.5 but,it seems strange that I can't find anything by Googling or
checking all the other Olds/Buick sites I went on that had ways to identfy differentials.Now this axle flange has me thinking
something isn't right about this.I'd appreciate any information that'll help identify this rearend before I spend more money on it.Thanks in advance for any help you can provide."Merry Christmas and Happy New Year". Bob

 

[grizwald]

that's how all the g body housings are. the top bolt hole is where the pin that holds all the springs for drum brakes goes. it also holds the top of the backing plate to the housing.

 

[thunderhead]

I guess that shows what I know.I've always had early 10-bolts or 12-bolts.This must mean I might as well forgot about the
disc-brake kit,right? I don't have a problem using the drum-brakes but,figured I might as well use them since I've got them.
I've got another 8.5 out of a '73-'77 Malibu I can use them with on another project.Thanks for the information. Bob

 

[grizwald]

no problem. i'm always glad when the little bit of info i have stored in my head can help someone! :lol:

 

[axisg]

To check at a glance look the bottom of the housing. If they stick out narrow and look like fangs it's a 7.5 rear. The 8.5 housing will have a squarded off block on either side of the diff cover bottom.

You can modify the axle ends by cutting off the top of the ends and drilling 2 new holes to mount your disk brakes ( depending on where you sourced the disk brakes )

 

[thunderhead]

Thanks for the reply.It's definitely a 8.5 and it's the correct width for a G-body but,it was the different flanges that I wasn't
familiar with.My '82 El Camino project I bought it for just got the body done and painted but,it's still about 1-1/2 drive from
my house at the guys shop that did it or I would have crawled uder it to see if it had the same style ends on the housing.I
have always had earlier 10-bolts or 12-bolts but,I learned something today about the G-body rearends.I'll probably just use
it with the drum brakes.I'm thinking about putting Ford ends on it and buying Ford style Moser axles so I don't have to deal with the C-clip eliminators.I'm probably putting a new 10-1 CR 383 with solid roller cam,Sportsman II heads,and tunnel-ram
with a single 950 HP carb in it.I already have everything plus a Powerglide with a 2.08 gear-set.I'll probably put 4.10 gears
in the rearend and I have M/T 26x10.5 ET Streets on 15x10 Rodlites,15x8 Rodlites with M/T 28x9 slicks,& 15x4 Rodlites with
Moroso DS-2 for the front.It will run mid to high-10's(promise)thru 1-3/4" Schoenfeld headers,& Borla XR-1 mufflers & I plan
on doing a lot of local driving & bracket racing it regularly.That's more than I planned on going into about it right now but,I guess I'm starting to get a little excited now that it's painted and got a little carried away.Again,thanks for the info. Bob

 

[prairiehotrodder]

The g-body housing ends are a pain, but you can buy brand new backing plates for them! You can cut them right off and weld on strange or moser ends that accept normal old style 10 bolt brakes and bolt-in axles (no c-clips) then you coul use your disc setup.
brian

 

[axisg]

don't give up on putting disks on that rear so easy. I put the LS1 rear brake setup on my 7.5 rear ( same flange as the 8.5 ) in under 3hours. With the rear caliper bolted on you don't have to worry about the c-clips coming out either.

Good luck with the build, sounds like it will be nice !!

 

[bbc_cutty]

don't give up on putting disks on that rear so easy. I put the LS1 rear brake setup on my 7.5 rear ( same flange as the 8.5 ) in under 3hours. With the rear caliper bolted on you don't have to worry about the c-clips coming out either.

Good luck with the build, sounds like it will be nice !!

you can buy brackets off ebay for $60 to run disc brakes on a 8.5

 

[thunderhead]

I just talked to a local guy that's coming by tomorrow to buy a cam and rocker arms from me.After talking to him a while,I found out he's narrowed quite a few rearend
housings and a lot of chassis and suspension work over the years.He said that to cut
off the factory flanges and weld new ones on,he'll only charge me $40.00 and that's
with a fixture he has to make sure they're straight.I think you know that I can't turn
that down so,it will have the disc-brake on it when it's put together.I already have a
30-spline posi,4.10 gears,TA support cover,and a pair of 30-spline Strange axles with
C-clip eliminators.I can get the axles cut down to size or I'm considering putting Ford
style flanges on it now if,I can get them with a Chevy 4-bolt pattern that will allow me
to still bolt the disc-brakes to.Then I won't need to use C-clip eliminators because,I'll
just order Ford style axles but,30-spline in the G-body length.Moser's price will be the same,no matter if they're Ford style or Chevy style,length doesn't make a difference either.All I have to do is tell them which bearing size I need.That will be easy because,
I'll order the ends,bearings,and axles from them and I can't go wrong.I talked to them
about doing this within the last 3 months and that is correct,price for the axles doesn't
change just because,they're Ford style with 30-splines,and the length I need.I guess
I better check into the Ford ends with GM 4-bolt pattern tomorrow so I know which
direction I'm going.Thanks for the replies. Bob