Looking for a 8.5 10 bolt

Captain Beaumont · Poncho Master!

Looking for a 8.5 10 bolt

GLHS60 · Poncho Master!

From the shellacking I received on another thread it seems 1972 Chevelles were equipped with an 8.5.

That's the only model I can think of, but I'm prepared for another spanking !!!

Thanks
Randy

http://canadianponcho.activeboard.com/t60217782/10-bolt-differential/

-- Edited by GLHS60 on Sunday 24th of May 2015 04:17:06 PM

-- Edited by GLHS60 on Sunday 24th of May 2015 04:19:51 PM

rabbit64cs · Canadian Poncho Superstar!

hehe.. it will fit, but is wider drum to drum .... and some say the upper a arm angle is a bit tight.. RAndy is correct

I have a 8.5 under my 67 Lemans.

you can put a 8.5 posi in a 8.2 housing .....

I'll let you search the net now.. I know a member on here that has done it , maybe he wil speak up.

GLHS60 · Poncho Master!

I'm not positive about this but it looks like 1970-72 Chevelles and Monte Carlos were all 8.5" !!
Might widen your search options.

I have an old email from someone offering me a 1971 Monte Carlo
12 bolt non posi for $300.00.

Ice Coffee might make me search for it if you're still dreaming of the extra 2 bolts, or .675". biggrin

Thanks
Randy

4SPEED427 · A Poncho Legend!

Most of the Monte's I've seen have been 12 bolts but there may have been 8.5" under them too.

I need to get into the parts book but in my head, there were no 8.5's in A body before 72. I was wrong many times before though, including many times today!

hawkeye5766 · Canadian Poncho Superstar!

rabbit64cs wrote:
hehe.. it will fit, but is wider drum to drum .... and some say the upper a arm angle is a bit tight.. RAndy is correct

I have a 8.5 under my 67 Lemans.

you can put a 8.5 posi in a 8.2 housing .....

I'll let you search the net now.. I know a member on here that has done it , maybe he wil speak up.

You can put an 8.5 posi in an 8.2 housing? I've got one sitting on my floor !!! and I have been looking for a 8.2 posi. What about ring and pinion? I'll have to go searching.

-- Edited by hawkeye5766 on Tuesday 26th of May 2015 09:16:57 AM

rabbit64cs · Canadian Poncho Superstar!

IT can be done, a memeber on here has done it , he may share his experience

I will search it out for you , found an article on one of the forums... how to .. takes some fab.. but your a handy guy !

GLHS60 · Poncho Master!

Carl Stevenson wrote:
Most of the Monte's I've seen have been 12 bolts but there may have been 8.5" under them too.

I need to get into the parts book but in my head, there were no 8.5's in A body before 72. I was wrong many times before though, including many times today!

I await your parts book examination!!

Some Chevelle sites say 8.5 were late 1972 only and others say 1970 -72

An early Monte Carlo site claims 8.2's were available during that period.

Another site says "some" BOP cars used Chevy 8.5's

No concern to me other than trying to get Terri some possible donor cars for his 1967

while I have been looking for a 1973-1977 A body 8.5 for my 1981 Parisienne with a 7.5.

Thanks

Randy

rabbit64cs · Canadian Poncho Superstar!

2 second google search...

http://www.camaros.net/forums/archive/index.php/t-81296.html

The 8.5 r&p set won't fit, but an 8.5 posi unit can be used in an 8.2 rear.
We used to use them before Eaton released the newer 8.2 units, because the 8.5 units were much easy to find.
Later,
Eric

big gear head

May 10th, 06, 07:41 PM

I'll have to look into this one. I know that the ring gear bolts are not the same size. The 8.2 uses 3/8 bolts and the 8.5 uses 7/16 bolts. I haven't checked on any of the other dimentions.

L72/RS

May 11th, 06, 05:11 AM

BGH,
We used a thin wall DOM tubing from Victory Tube Products to make sleeves for the ring gear bolts.
I think the only other mod required was some of the castings needed to cleaned up for clearance on the passenger side of the case.
I will see if we still have one of the old setups on the rack and post a picture.
Later,
Eric

John65nova

May 11th, 06, 05:52 AM

Really? You can use an 8.5" posi in an 8.2"? I guess a 3-series 8.5 diff would be used with 3-series 8.2" gears?

I'd love to learn more about this... 8.5" posi units seem to be plentiful.

GLHS60 · Poncho Master!

Putting the 8.5 in the 8.2 is a great up grade, possibly very cheap!!

Edit: This is not a direct fit but the modifications would be doable for determined folks!!

I remember an old Hot Rod magazine when I was a kid about some guy Pepe Estrada in the U.S. installing 12 bolts in IRS corvettes. Could the orig. Corvette IRS diif have 8.2's??

Thanks
Randy

-- Edited by GLHS60 on Tuesday 26th of May 2015 07:07:35 PM

hawkeye5766 · Canadian Poncho Superstar!

Thanks Rog!! Looks like there might be some more fab work in my future. smile Will post when I tackle it.

Beaumont4008 · Uber Guru

Your only using the carrier with this mod and not the 8.5 ring and pinion. You have to use the 8.2 ring and pinion On the 8.5 carrier with spacers for the ring gear bolts.

4SPEED427 · A Poncho Legend!

GLHS60 wrote:

Carl Stevenson wrote:
Most of the Monte's I've seen have been 12 bolts but there may have been 8.5" under them too.

I need to get into the parts book but in my head, there were no 8.5's in A body before 72. I was wrong many times before though, including many times today!
I await your parts book examination!!
Some Chevelle sites say 8.5 were late 1972 only and others say 1970 -72
An early Monte Carlo site claims 8.2's were available during that period.
Another site says "some" BOP cars used Chevy 8.5's
No concern to me other than trying to get Terri some possible donor cars for his 1967
while I have been looking for a 1973-1977 A body 8.5 for my 1981 Parisienne with a 7.5.

Thanks
Randy

I can pretty safely discount the "late" 72 theory. My mom took delivery of her brand new 72 307 Malibu just before Christmas 1971 and it had an 8.5".

Now, to see what the parts book says...

4SPEED427 · A Poncho Legend!

Well, this is interesting-

From the Chevelle/Monte parts book, here's the listing for the diff covers-

3976850 64-71 10 bolt cover- Chev axle

3852998 65-69 12 bolt cover

3976857 70-72 12 bolt cover

9777035 70 Monte Carlo with Pont axle-10 bolt cover

6270962 72 10 bolt cover
73-74 all except wagon

9790538 73-74 wagon

There's 2 different 12 bolt covers for a Chevrolet?

ALL 72 Chevelle and Monte 10 bolts are 8.5"?

70 Monte used the BOP 10 bolt?

One thing to remember, this is from the Canadian book and we know real well that diff usage between Canada and the US was not the same from the mid 60's and up in both B body and A body it appears.