Switch to disc in rear

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Originalowner73 340duster

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I have a 8 3/4 rear and want to do disc brakes in rear and better system in front ..is their a kit if so which is the way to go..and do I have to change Axel's?
 
There are several kits available for disc brake conversion for your 8 3/4" rear . There were several variants of the 8 3/4 and it is essential that you measure correctly . The critical measurement is from the axle flange to the face of the housing (called the brake space ) so that the caliper is spaced properly . Not difficult but important .
 
There are several kits available for disc brake conversion for your 8 3/4" rear . There were several variants of the 8 3/4 and it is essential that you measure correctly . The critical measurement is from the axle flange to the face of the housing (called the brake space ) so that the caliper is spaced properly . Not difficult but important .
 
Dr Diff makes a great F/R disc conversion.
They are very knowledgable to fitting the correct one for you.
Give them a shout
 
I considered this upgrade but decided against it and went with Moser 4.5 bolt circle axles, and 11x2.5" rear heavy duty finned drums. Why?? Because removing the factory drum setup and going with disks removes too much weigh from the rear and further exasperates the front to rear weight bias resulting in poorer handling characteristics. In my case, I went with Alterkation front suspension and Wilwood front disk setup which is much lighter than stock. Along with the aluminium heads and intake manifold I'm taking weight out of the front and moving it rearward to even out the weight distribution. Hopefully Ill end up with a much better handling car.
 
I considered this upgrade but decided against it and went with Moser 4.5 bolt circle axles, and 11x2.5" rear heavy duty finned drums. Why?? Because removing the factory drum setup and going with disks removes too much weigh from the rear and further exasperates the front to rear weight bias resulting in poorer handling characteristics. In my case, I went with Alterkation front suspension and Wilwood front disk setup which is much lighter than stock. Along with the aluminium heads and intake manifold I'm taking weight out of the front and moving it rearward to even out the weight distribution. Hopefully Ill end up with a much better handling car.
I didn't consider the weight because I didn't think it would be enough to make a difference..was more worried about stopping force..but will definitely consider that in my final decision
 
Well , here's some other things you may want to consider as well. Your car weighs about 3200lbs. If you have disks up front and you increase the size of the rear drums, now you have even more stopping power with the 11 "drums. It was good enough for a Hemi Cuda or Roadrunner and they weighed 35-3800lbs. Remember, the front brakes will do most of the stopping anyway. A big plus is that you gain this advantage at a much lesser price , approx. 250-300.00 vs 800-1000 dollars for rear disks !!
 
I didn't consider the weight because I didn't think it would be enough to make a difference..was more worried about stopping force..but will definitely consider that in my final decision
I considered this upgrade but decided against it and went with Moser 4.5 bolt circle axles, and 11x2.5" rear heavy duty finned drums. Why?? Because removing the factory drum setup and going with disks removes too much weigh from the rear and further exasperates the front to rear weight bias resulting in poorer handling characteristics.

this should not be the case at all. It is unsprung.
IF anything, the disc will weigh less and allow the car to go faster.
IF it was "Sprung weight" on the car, then you have something.

Dr.Diff has kits that will help out. You can re-use your old wheels and tires. Not an issue. Upgraded axles can also be had at Dr.Diff but IIRC, only in the larger 5X4-1/2 pattern. Upgarding the front discs to a 5X4-1/2 is also an EZ kit away. Factory or not.
 
Well , here's some other things you may want to consider as well. Your car weighs about 3200lbs. If you have disks up front and you increase the size of the rear drums, now you have even more stopping power with the 11 "drums. It was good enough for a Hemi Cuda or Roadrunner and they weighed 35-3800lbs. Remember, the front brakes will do most of the stopping anyway. A big plus is that you gain this advantage at a much lesser price , approx. 250-300.00 vs 800-1000 dollars for rear disks !!
Thanks alot ..will definitely be taking his info into consideration..and the save money part is huge!!
 
Well , here's some other things you may want to consider as well. Your car weighs about 3200lbs. If you have disks up front and you increase the size of the rear drums, now you have even more stopping power with the 11 "drums. It was good enough for a Hemi Cuda or Roadrunner and they weighed 35-3800lbs. Remember, the front brakes will do most of the stopping anyway. A big plus is that you gain this advantage at a much lesser price , approx. 250-300.00 vs 800-1000 dollars for rear disks !!
I do agree with this to a point. A new proportioning valve should be used. Or an adjustable one. While itis not the end of the world, it is a helpful item to have. If cost is a consideration, stay with stock parts and retro fit them.it is mostly an E Z task.
 
I do agree with this to a point. A new proportioning valve should be used. Or an adjustable one. While itis not the end of the world, it is a helpful item to have. If cost is a consideration, stay with stock parts and retro fit them.it is mostly an E Z task.
Looking for what's best and safest not so much on saving money..but it does help to save where you can
 
Well, safer is always first in my book, but, I have no actual practical experiance with aftermarket brake systems. The stock parts have been good enough for what I was doing. Best runs were high 11's. Stopping power was not an issue @ 110+ on factory parts in a full weight E body.
 
this should not be the case at all. It is unsprung.
IF anything, the disc will weigh less and allow the car to go faster.
IF it was "Sprung weight" on the car, then you have something.

Dr.Diff has kits that will help out. You can re-use your old wheels and tires. Not an issue. Upgraded axles can also be had at Dr.Diff but IIRC, only in the larger 5X4-1/2 pattern. Upgarding the front discs to a 5X4-1/2 is also an EZ kit away. Factory or not.

I would agree to a point. The power train will have less effort in spinning lighter rotors and rebound in the suspension will be a little harsher with more unsprung weight. However, by moving more weight rearward, the vehicle moves away from being nose heavy and should handle a little better. You are still accelerating the same mass whether it is sprung or unsprung weight so Im not sure it would be faster. The biggest point I would make is that there is not enough difference made in the car's braking for the amount of money spent to convert to disk rather than bigger drums.
 
Well, safer is always first in my book, but, I have no actual practical experiance with aftermarket brake systems. The stock parts have been good enough for what I was doing. Best runs were high 11's. Stopping power was not an issue @ 110+ on factory parts in a full weight E body.

Yup! Have to agree here. Excellent example is that your e-body's rear brakes work fine and are completely safe. BTW , were they 10 or 11"?
 
Stupid question but what

Is the e body.. thought I had a body..right??
Yes! just mentioning my E-body Cuda because it has factory braking and weighs a bit more than an A body. The "Listed" cars weight is IIRC, 3650lbs. P/S, P/B, no A/C, small block, 4 spd manual, 8-3/4 rear, S/S springs. Basic MP book build parts back from the early - mid 80's.
I would agree to a point. The power train will have less effort in spinning lighter rotors and rebound in the suspension will be a little harsher with more unsprung weight. However, by moving more weight rearward, the vehicle moves away from being nose heavy and should handle a little better. You are still accelerating the same mass whether it is sprung or unsprung weight so Im not sure it would be faster. The biggest point I would make is that there is not enough difference made in the car's braking for the amount of money spent to convert to disk rather than bigger drums.
No,the drums are not sprung so weight transfer is unaffected. The weight is otherwise dead mass that needs to be rotated or pushed. All of this has been writen about and proven by smart people, not smart *** smarty pants people like me.
Yup! Have to agree here. Excellent example is that your e-body's rear brakes work fine and are completely safe. BTW , were they 10 or 11"?
Stock for '73, 10 drums, small disc up front. It was a bit hairy stopping, but that is mostly a issue of nerves. Plenty of run at the strips end. A lack of vacuum has more play and is the scarry issue if it isn't there! A nervous LOL at tracks end for the new guy!
 
Sorry for the confusion Originalowner73, but the E body and the A-body were both available with 10"brakes. By using the backing plates and drum setup from an e-body with 11" brakes, you could upgrade to the larger brakes on your a-body.
This is exactly what I did with my car.
 
I did a similar move. I took the 11 inch drum set up from backing plates outwards from a Cordoba years back. I also grabbed the larger 12 inch discs. Wish I still had the disc set up! I have the drums set up.
 
Off the to
Yes! just mentioning my E-body Cuda because it has factory braking and weighs a bit more than an A body. The "Listed" cars weight is IIRC, 3650lbs. P/S, P/B, no A/C, small block, 4 spd manual, 8-3/4 rear, S/S springs. Basic MP book build parts back from the early - mid 80's.

No,the drums are not sprung so weight transfer is unaffected. The weight is otherwise dead mass that needs to be rotated or pushed. All of this has been writen about and proven by smart people, not smart *** smarty pants people like me.

Stock for '73, 10 drums, small disc up front. It was a bit hairy stopping, but that is mostly a issue of nerves. Plenty of run at the strips end. A lack of vacuum has more play and is the scarry issue if it isn't there! A nervous LOL at tracks end for the new guy!


Off the topic...sorry.. but that was one quick E-body for the 'eightys' !! I saw big block e-bodys run back then that you would have decimated!! Good on ya!
 
Sorry for the confusion Originalowner73, but the E body and the A-body were both available with 10"brakes. By using the backing plates and drum setup from an e-body with 11" brakes, you could upgrade to the larger brakes on your a-body.
This is exactly what I did with my car.
..makes sense..I was lost for a second.hahaha
 
Well,
Off the topic...sorry.. but that was one quick E-body for the 'eightys' !! I saw big block e-bodys run back then that you would have decimated!! Good on ya!
Well, maybe! I did recieve a few real good stompings as well. I called the tech line and told them I was tired of a few *** clowns talking crap after getting whooped. After a short discusion, he told me to go with W2's and a upgraded cam &header. I never got to the W2's though. (Actually, I just picked up my first pair. Some 30 years later after the advice. But kids, house, marriage, collage, ......)
I just followed the MP "Speed Tips" section in there publications. Get these parts, numbers listed, follow the list, skip the 6 pack, (WHOA! $$$$!!!) yadda yadda yadda.... Just lookup the part number, go down to the dealer the old club had a deal with (10% over cost on everything except cloths) and order away. 1 of the parts guys used to work on the tech line until he moved to New York. Larry was a real nice and good fella.
 
I was running this (Screwed up so it had to be welded up) MP book modified LD-340 for a long time with a big TQ and cam.
Then I found for a stupid cheap price, the 6 pack below it. LeAnna power coated it for me as well as the MP - M1 tunnel ram.
Then there is the W5 set up on dragging my feet on.
YUP (I have bitten off more than I can chew at the moment. But thats OK. I don't mind these fresh parts collecting dust for a little while.)
Soon, I'll get to play with blocks again.
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