8 3/4 build questions

-
C

carcrazyguy

Well-Known Member
Joined
Feb 5, 2005
Messages
1,358
Reaction score
16
Location
Amarillo, TX
I have a complete 8 3/4 out of a 72 Charger that has a 489 center section. I am currently trying to work a deal to buy an A-body 8 3/4 housing. Will the drums and backing plates from the 72 B-body rear work on the A-body housing? Also I will need to buy axles. Would the stock (A body) length still work if I use the 72 Bbody brakes and backing plates????

Thanks in advance!! :thumleft:
 
All the 8 3/4 backing plates will bolt up,what would be different is the size of the brakes themselves.
Most B-body drums are 11inch and A-body 8 3/4 are 10inch.
 
Well I am going through the same thing right now! From what I have been told as long as your car had big bolt pattern you should be able to swap the brakes other wise they won't swap. Also I don't think all backing plates are the same but i could very well be wrong about that!
 
Well I had planned to change to big bolt pattern anyway so I could run Weld ProStars. So the big brakes and big bolt pattern should not be a problem in my case. I just hate to spend $300 on an A-body housing and then have to find all the parts to work with it. If I was going to have that issue I think I would rather just order a Moser 60 :lol:
 
I am doing some brake swaping right now myself. This is what I have found out. You can use any brakes you want from one rear to another. This is the limiting factor, you have to move the complete brake assembly. This means the backing plates, cylinders, pads and drums, along with all of the small parts. You can use the brakes from a 5 on 4 axle on a 5 on 4 1/2 axle as long as you get the drums redrilled to the proper pattern. Everything else bolts right on. To prove this to myself, I took the brake system off of a 7 1/4 rear and tried to put it on a 8 3/4. Guess what, the only thing I had to do was drill 3 new mounting holes in the backing plate. Everything else fit perfect. The same goes for using a 9 1/4 brake system. Only difference is you don't have to drill the backing plate.

Jack
 
If you use the B-body brakes on the A-Body rear there is a .25 difference in off set, Which means you have to get different axles or have b/c axles cut down. The difference is between the flange and the bearing.
 
I had planned to order new axles anyway since the 8 3/4 that I am planning to buy is just the housing.

Here is what I planned to do. Tell me if you see anything that won't work.

I have a 72 Charger 8 3/4 with 489 case
Buying an A body housing. BARE
pull the center section of the Charger rear
pull backing plates and brake parts off Charger rear
Take all parts and A body housing to a shop for rebuild
order axles when they tell me what they need
may change gears from 3.23 suregrip to 3.91's :scratch:
 
mopwer71 is right on the money with the axle issue. what you are planning to do is correct. The key is getting the right axles.
 
You must log in or register to reply here.
-

Back
Top