rear end housing

[SPOOLN]

rear ends

I am not sure but i think the rears that came in the 78-88 Older Impalas and Oldsmobiles, Buicks have the 8.5 rear housings. Regal Station wagons Pontiac station wagons and Caprice should have them. GM is not going to tool up just for GNs and Olds 442s, They want to make it worth their while.

 

[GNVAIR]

Re: rear ends

Originally posted by SPOOLN
I am not sure but i think the rears that came in the 78-88 Older Impalas and Oldsmobiles, Buicks have the 8.5 rear housings. Regal Station wagons Pontiac station wagons and Caprice should have them. GM is not going to tool up just for GNs and Olds 442s, They want to make it worth their while.

This comes up over and over again. The only 8.5 10 bolt that will fit a G body without any mods is the one used in the 84 Hurst Olds, 85-87 442 and 84-87 Turbo Regals. The B body rears will not fit. The angles are different on the upper control arms and the housings are way too wide.
GM did tool up a special rear for the G body as the G bodies have a 2 3/4" or 2 5/8" diameter axle tubes. Basically the G body 8.5 uses the same axle tubes as the more common 7.5 rears. 8.5's used in other GM vehicles have 3" axle tubes.

 

[85 t-tizzle]

442 rears also have 373 gears instead of 342's that come in gn's

 

[abro5011]

Cheap 11" drum brakes for our cars

Ah ha---Did anyone know that 77-78 monte-carlos and some chevy and buick estate wagons of around that year had 11" rear drum brakes,compared to the 9" ones on our cars that with a little modification will adapt to our rear ends. To hell with the S-10 wheel cylinders, wanna hold more boost on the launch---this here is a low buck set-up with a little work. Our rear ends have a rectangular metal bracket welded to the end of the axle tubes, and bolt the backing plate on with 2 bolts on the bottom and a big special bolt on the top that also holds the brake springs and mounts the top of the brake pad. Well--all ya gotta do is cut that rectangular off at the top to make it square and drill the 2 top bolt holes to match the 11" backing plate. ( it has 4 bolts in a perfectly square pattern) The bottom bolts will already match. This backing plate already has the mounting bolt for the top mounting for the springs and brake pads welded on. Actually it isn't a bolt, but a machined piece welded. I have done this modification to mine so I can answer any questions you might have. I guess the hardest thing was finding the 77-78 Monte-carlo or station wagon backing plates and drums.

 

[Geoff87]

Re: Cheap 11" drum brakes for our cars

Nice info! Can you post a link to some pics?

Originally posted by abro5011
Ah ha---Did anyone know that 77-78 monte-carlos and some chevy and buick estate wagons of around that year had 11" rear drum brakes,compared to the 9" ones on our cars that with a little modification will adapt to our rear ends. To hell with the S-10 wheel cylinders, wanna hold more boost on the launch---this here is a low buck set-up with a little work. Our rear ends have a rectangular metal bracket welded to the end of the axle tubes, and bolt the backing plate on with 2 bolts on the bottom and a big special bolt on the top that also holds the brake springs and mounts the top of the brake pad. Well--all ya gotta do is cut that rectangular off at the top to make it square and drill the 2 top bolt holes to match the 11" backing plate. ( it has 4 bolts in a perfectly square pattern) The bottom bolts will already match. This backing plate already has the mounting bolt for the top mounting for the springs and brake pads welded on. Actually it isn't a bolt, but a machined piece welded. I have done this modification to mine so I can answer any questions you might have. I guess the hardest thing was finding the 77-78 Monte-carlo or station wagon backing plates and drums.

 

[Intercooled88s]

abro5011 do you have any pictures, any other full size cars have those brakes. How much difference have you noticed?

 

[HI85WH1]

I would think that those rears (73-38 A body would be easy to find...)

but yes, the mod works... did it on my 81 el camino... I always thought it was a little "ghetto", but since someone else has done it, I guess it is OK...

I'm glad to know I'm not the only one who thought of that...

Sorry, no pics of mine... I did this back in 87-88...

 

[Intercooled88s]

HI85WH1 what did you think of the brakes?

 

[HI85WH1]

in a nutshell? much better than stock...

I did the B body fronts as well with the shaft-as spacer option...

worked fine... and no more warped rotors.

 

[Geoff87]

Let me know if you find any Rob......

 

[HI85WH1]

No problem Geoff.

 

[GNVAIR]

Re: Cheap 11" drum brakes for our cars

Originally posted by abro5011
Ah ha---Did anyone know that 77-78 monte-carlos and some chevy and buick estate wagons of around that year had 11" rear drum brakes,compared to the 9" ones on our cars that with a little modification will adapt to our rear ends. To hell with the S-10 wheel cylinders, wanna hold more boost on the launch---this here is a low buck set-up with a little work. Our rear ends have a rectangular metal bracket welded to the end of the axle tubes, and bolt the backing plate on with 2 bolts on the bottom and a big special bolt on the top that also holds the brake springs and mounts the top of the brake pad. Well--all ya gotta do is cut that rectangular off at the top to make it square and drill the 2 top bolt holes to match the 11" backing plate. ( it has 4 bolts in a perfectly square pattern) The bottom bolts will already match. This backing plate already has the mounting bolt for the top mounting for the springs and brake pads welded on. Actually it isn't a bolt, but a machined piece welded. I have done this modification to mine so I can answer any questions you might have. I guess the hardest thing was finding the 77-78 Monte-carlo or station wagon backing plates and drums.

Actually its 73-77 A body wagons. Possibly some 73-77 A body coupes/sedans, but that is doubtful. Most of the 73-77 sedans I have seen used the same 9" style rear drums as used on the 64-72 models. The flange you are talking about is the small standard GM flange. Best way to do the swap is the reflange the housing.
The 78-88 G bodies have the "Metric" flange which is tall. It attaches the backing plate with 2 tiny 6 or 7mm screws at the bottom and a 22mm nut attached to the anchor pin. Its just a jerked off set up. Regardless, this thread was about axle housings. The only true bolt in is the 84-87 Olds/Buick G body 8.5 10 bolt.