BRAKE DRUM QUESTION

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WAYNE0

WAYNE0

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The 71 demon im working on for a guy has 10 inch rear drum brakes. I talked him into changing it to big bolt pattern. I want to keep the same size rear brakes. Does anyone know what car i can use the brake drums from ? It will have to be some thing that had big bolt pattern with 10 inch rear brakes.
 
There are no other vehicles with those drums. If you drilled original 4" bolt axles or bought axles with 4-1/2" pattern and want to keep the 10x1-3/4 brakes then you have to use what you have and drill the drums.
 
Exactly.

The only cars that had 10x1-3/4” drum brakes were A-bodies that had the 5x4” pattern.

The 5x4.5” bolt pattern drums were 10x2.5”, and those axles use a different axle flange stand-off so the backing plate offset is different.

If you want to keep the 10x1.75” drums but use a 5x4.5” pattern you need to re-drill the stock SBP axles or buy axles that have the SBP axle flange offset and the drums must then be re-drilled for the 5x4.5” pattern.

Otherwise you need to use BBP axles with 10x2.5” drums and backing plates. No mixing and matching!

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It all depends on how you go about changing the bolt pattern.
If you just redrill the stock axles, you need to redrill the stock drums, too. There's no 5x4.5 drum that will match your backing plates and have the correct center register.
4"to 41/2 what backing plates
If you are ordering aftermarket axles with the standard Mopar flange offset (not the A body offset), then any mid or full size Chrysler, some trucks and vans will have what you need, but you MUST use the matched backing plates. Period. There are no 5x4.5 drums that work with A body backing plates.
What rear drums for 4.5" axle swap
 
Treed me, 72bluNblu... seems like we're answering this every other day. Think we need to come up with a sticky so we don't have to type it all out over and over.
 
WAYNE0 said:
Dr.diff axles with green bearings and drum wheel studs
Click to expand...

Then you will need to find 10x2.5" drums and backing plates, the 10x1.75" brakes will not fit those axles because they use the BBP flange offset.
 
i ordered from DR.DIFF stock length green bearings drum wheel studs so if i got every thing from a B body that had 10x2.5 rear brakes i should be fine sorry guys this is new to me
 
WAYNE0 said:
i ordered from DR.DIFF stock length green bearings drum wheel studs so if i got every thing from a B body that had 10x2.5 rear brakes i should be fine sorry guys this is new to me
Click to expand...

All Mopar BBP axles use the same axle flange offset. You can pull 10x2.5" rear brakes off of ANY Mopar with a 5x4.5" pattern.

Right from the DoctorDiff website...

"A-body "big bolt pattern conversion axles" fit any '65 and newer, 5 x 4 1/2" Mopar spec rear disc or rear drum brake assembly. These axles will NOT fit 5 x 4" bolt pattern brake assemblies, backing plates or re-drilled drums"
 
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