Joker13
Well-Known Member
What Small bolt pattern backing plates do I need for 8.75 rear I’m building for 68 Barracuda.
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8 3/4 Backing plates SBP question
- Thread starter Joker13
- Start date
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j061093409
1970 Dart Swinger 340 Reg
I should have some loaded units. Can check after work. In CT
FYI 7 1/4 10x1 3/4 backing plates are a direct swap.
The hole in the center of the plate is smaller on the A body 7.25 than on the 8.75. Wont fit over the axle bearing. (72 back)
7.25 plate wont fit 8.75 axle.
Shoes, levers, etc. are the same.
News to me... A few years ago I was assured the 7 1/4 10x1-3/4 brakes were a direct swap to an 8 3/4.
The bare plates on the floor pictures above are 7 1/4 look at the different bolt pattern on the 8 3/4 first picture above . The last picture are fronts.
72 back won't fit, different axle flange size and bolt pattern.
73-76 A body I believe fit. Still used the 10x1.75 brakes but used common axle flange pattern.
76 up for sure. Just tore another late 70s 7.25 apart last week. Direct fit.
But those are 10x2.5 shoes for 76 up.
To all who have posted here: I changed this thread to a question thread because it seems there may be multiple choices and until the right answers come out there's no sense in selling him something that isn't what he needs. Don't try to sell the OP a set you have here on the thread. Respect the rules and send him a PM instead. Thanks
73 -76 7 1/4 backing plates for big bolt pattern will not work. They will only work with big bolt pattern drums the offset of the backing plate is different for the wider shoes. A good reference is if you go to install big bolt axles and use the big bolt drums with small bolt backing plates the drum hits the backing plate. The reason why everyone is always looking for big bolt backing plates when when installing after market axles.
I was refering to 73-76 A body 7.25 small bolt brakes w 10"x1.75" shoes, thats why I mentioned them specifically.
Big bolt stuff was mostly 2-1/2".
I believe most of the 10X1.75 parts...shoes, drums, wheel cyls, etc. are interchangeable EXCEPT the backing plates are not.
72 back small bolt 7.25 plate left , large bolt 10"x2-1/2" right (same flange as 8.75)
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8.75 shim laid over 72-back 7.25 10" x 1.75" backing plate.
flange stud holes dont line up and center is much smaller.
Thanks for the confirmation with photos. I checked the backing plates I bought and luckly they are correct for 8 3/4 and have 1-3/4 shoes. Glad I bought them as my original plan was to reuse my 7 1/4s
No problem. I mentioned it enough so figured pics were in order
Pic worth 35 words!
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