Hey guy's. Just about got everything for my 7 1/4 to 8 3/4 conversion. Will the backing plates from my 7 1/4 fit my 8 3/4? This is a 67 barracuda with 10" drums. Thanks

Post deleted by DusterKrazy

I think you have to add the 5th hole

That's what I was thinking, but the different diameter of the housing got me wondering. Anyone else?

I'm thinking they will not work. The 8 3/4 has 10 inch drums, while the 7 1/4 has 9 inch drums.

they wont interchange, offset is different

You will need plates from a 8 1/4 or 8 3/4, the 7 1/4 ones will not work.

Okay, Now I am confused, I am Pretty sure my 7 1/4 has 10" backing plates. It seems a lot of 8 3/4 have 10'' plates on them stock. I did have to change U-bolts and Spring plates, but I would think my backing plates would work. I need all the opinions I can get. Thanks

I'm almost positive that the diameter of the flange end/brg is different so the diameter of the bolt circle on the plates is different.

I know that some 8 1/4's had only 4 holes, and you could knock in the 5th hole to make it work, but not on a 7.25.

I don't think you'll know for sure till you try, but I doubt very much it will work

The 7 1/4 plates have 4 bolt holes for the axles, the 8 3/4 have 5.

You guy's are right! I just went out and looked and my 7 1/4 plates have 4 holes and the flange on my housing has 5. I need to get some plates now. Should any 8 3/4 10'' backing plate work or do they need to be A-body correct. I have all ready found some cheap on evilbay from a 8 3/4 B-body but they look exactly the same. Thanks a million....

what axles do you have? stock A-body? stock A-body housing? did you have one cut down to A-body specs?

as long as you have axle with the large brake offset,B-C-truck 8 3/4 axles,or moser axles or some other after market axles

7 1/4 wont work and the skinny A-body 8 3/4 brakes wont work with the large brake offset axles

any brake set up of a 8 3/8,9 1/4,8 3/4,9 3/4

A,B,C-body and truck will work

I used 73 bp and 11x2.5 brakes from a 73 newport on my 68 dart going from 7 1/4 to 8 3/4,I did up to the largest wheel brake cyls

11s are a little big/heavy,but the stopping power over the 10s was very noticable with hard braking,auto-x style,almost no fade

I had the large 12" rotors from an R-body on my A-body spindles with a MP 4 bolt mc to 2 bolt alum mc adapter with a 79 truck alum mc,all manual brake even had air scoops on the front dust sheilds for cooling of the rotors

braking power is transforming friction into heat,bigger is better