Author Topic: Stock 73 E-body 8.75 rear drum vs dr diff kit?  (Read 3563 times)

Offline carcrazyguy

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Stock 73 E-body 8.75 rear drum vs dr diff kit?
« on: March 10, 2015 - 11:52:15 PM »
What was the size of the rear drum brakes on the 73 E-body 8.75 rear ends?  Were they larger than the rear brake kits that Dr Diff sells? 

http://www.doctordiff.com/mopar-10-x-2-1-2-drum-brake-assembly.html



Trying to decide on buying each piece to rebuild the brakes on the rear end or ordering the full assembly from Dr. Diff when I order the front 11.75 disc set up and the 8.75 center section.




Offline Chryco Psycho

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #1 on: March 11, 2015 - 12:30:31 AM »
10 x 2.5" would be the stock size , , if you use the truck wheel cylinders [different diameter]  the rear brakes will not lock up first with front disc

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Offline carcrazyguy

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #2 on: March 11, 2015 - 12:51:48 AM »
 So you are suggesting that I purchase the truck wheel cylinders if I go back with either the stock of dr. diff drum kit?

Offline crash340

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #3 on: March 11, 2015 - 05:51:15 AM »
What year and model Truck should I aim for when Im on Rockauto's web site Neil please. My rear brakes lock up if im breaking into a corner, straight line they are pretty good
Greg

73 Cuda
Brisbane, Australia

Offline bc3j

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #4 on: March 11, 2015 - 09:02:15 AM »
I used the 13/16" wheel cylinders from a '91 Dakota with 10" rear brakes. The Dakota with 9" brakes has a 7/8" wheel cylinders.

Offline Chryco Psycho

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #5 on: March 11, 2015 - 02:08:03 PM »
Check with Brad , he used a specific wheel cylinder , easy to get

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Offline brads70

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #6 on: March 11, 2015 - 03:24:52 PM »
I used the truck wheel cylinders when I had drum brakes. Worked great with no lock up before front wheels locked up Stock bore is 15/16" and the trucks is 7/8" (Raybestos WC37236, DORMAN  W37236). 
I now have the DrDiff  rear disc kit ( small) works great too. 
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

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Offline crash340

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #7 on: March 11, 2015 - 03:58:08 PM »
Brad, were they are direct bolt in item to the Mopar E body back plate and line?
Greg

73 Cuda
Brisbane, Australia

Offline bc3j

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #8 on: March 11, 2015 - 06:29:45 PM »
Mopar Action June 2013 had an article on drum brakes and the cylinders. The article had 3/4", WC37863; 13/16" WC37696; 7/8" WC37236. Mine were direct bolt ins with the exception of the bolts which needed a different thread count. I tried my OEM bolts and they didn't thread correctly. Don't know what's up with that. Everything did line up correctly.

Offline brads70

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #9 on: March 11, 2015 - 06:52:04 PM »
Brad, were they are direct bolt in item to the Mopar E body back plate and line?

Yep! :2thumbs:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
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 My handling upgrade post
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Offline dodj

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #10 on: March 11, 2015 - 09:53:39 PM »
With how light the rear is on these cars, ie the stock drums locking up early, what advantage are the discs. I seem to think we don't need to improve the braking ability of the rears? :dunno: Or is it an unsprung weight thing?
Scott
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Offline brads70

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #11 on: March 11, 2015 - 09:55:46 PM »
With how light the rear is on these cars, ie the stock drums locking up early, what advantage are the discs. I seem to think we don't need to improve the braking ability of the rears? :dunno: Or is it an unsprung weight thing?

"Bling" and pad selection  :lol:
Brad
1970 Challenger 451stroker/4L60 auto OD
Barrie,Ontario,Canada
Proud to own one of the best cars ever made!!!!!

My restoration thread 
http://www.cuda-challenger.com/cc/index.php?topic=59072.0
 My handling upgrade post
http://www.cuda-challenger.com/cc/index.php?topic=73985.0

Offline 73restomod

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #12 on: March 12, 2015 - 09:30:24 AM »
Disc vs. Drum, comes down to use, specifically frequency, if you got a daily driver that's driven briskly occasionally than stick with drums, you would be ok even with the occasional hot lap at the autocross. When disc would be mandatory, in my opinion, is when you will be doing multi-hot pass racing where consistency would be beneficial to both lap times and safety.

Offline crash340

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #13 on: March 13, 2015 - 05:39:04 PM »
Wow, rear brake lock up must have been worse back in the day with the larger 11" rear drums, kinda glad I only have the smaller!!
Greg

73 Cuda
Brisbane, Australia

Offline GoodysGotaCuda

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Re: Stock 73 E-body 8.75 rear drum vs dr diff kit?
« Reply #14 on: March 13, 2015 - 09:34:44 PM »
As one that likes to trail-brake, I will feel a little more confident and more consistent running rear discs. I've never cared for drums in applications other than parking brakes or econo cars.  :icon16:

...not to say you can't race when them, I just prefer not to if I can help it.
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1972 Barracuda - 5.7 Hemi + T56 Magnum

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