Correct Backing Plates

[money pit]

I bought a 8 3/4 rear end housing and axles, without the backing plates. The rear end was on a 71 challenger, I have a 70 Barracuda, originally a slant six. I currently have the 7 1/4 rear end. On the 8 3/4 rear end, I know the drums are supposed to be 11 inches. What size backing plates do I need? I saw two different widths, 11 x 3 in and 11 x 2 1/2 inches. Would it be better to convert to discs rather than staying with the drums? I plan on using the car as a daily driver. Thanks

 

[TC_Cuda]

I am not a break expert but I do know that the standard breaks used on 8 3/4 rear end was a 10" break and not the 11"
Even with power front disk breaks 10" was used on the rear no mater which rear end you had. I believe that the 11" was an option back in the day and would have been 11" by 2 1/2 and
would have been 11" front and back. What do you have on the front ? With a 6 cylinder car it would most likely be 10" drum but even with a 6 cylinder you could order power disk.

 

[money pit]

The front brakes are actually discs. I had a 8 3/4 rear end that I sold, that had 11 inch brakes so I wasn't sure it used 10 or 11 inch drums and backing plates. Thanks.

 

[Chryco Psycho]

I believe the rear brakes were different depending on the front brakes so you would have 11" front & rear if it was drums with 3" on the front & 2.5" on the rear .
If you had front disc the rear were 10" drums , .
I would swap the brakes from the rear you are removing from the car [7 1/4"] & use those as they will match the front brakes & proportioning valve you have .

 

[money pit]

I believe the rear brakes were different depending on the front brakes so you would have 11" front & rear if it was drums with 3" on the front & 2.5" on the rear .
If you had front disc the rear were 10" drums , .
I would swap the brakes from the rear you are removing from the car [7 1/4"] & use those as they will match the front brakes & proportioning valve you have .

If everything will bolt up that would be great. Thanks.

 

[Chryco Psycho]

It will bolt up , I have swapped them before .

 

[money pit]

It will bolt up , I have swapped them before .

That's great to hear. Thanks. I appreciate your advice.

 

[money pit]

It will bolt up , I have swapped them before .

That's great to hear. Thanks. I appreciate your advice.

That's great to hear. Thanks. I appreciate your advice.

Do you know if a third member from a 72 D100 pick up, 741 housing hit? Are all 8 3/4 housing the same? It has 355 gears. Thanks.