A Body Disc Brake Swap 101

Did this thread help you out?

  • Yes

    Votes: 262 94.2%
  • No

    Votes: 16 5.8%

  • Total voters
    278
-
I am looking at the straight up swap for disc brakes front conversion for my wife's 68 four door dart. I see both the mancini and doctor diff kits. No chance of finding a donor car for this on the big island of Hawaii! Disc conversion is a priority for safety. I want it soup to nuts, don't want to get into and have anything missing. What's the recommend on this? The valiant in my avatar, I just took the whole front end off a disc brake duster. No chance of that where I live now!
 
I am looking at the straight up swap for disc brakes front conversion for my wife's 68 four door dart. I see both the mancini and doctor diff kits. No chance of finding a donor car for this on the big island of Hawaii! Disc conversion is a priority for safety. I want it soup to nuts, don't want to get into and have anything missing. What's the recommend on this? The valiant in my avatar, I just took the whole front end off a disc brake duster. No chance of that where I live now!

i used dr diff. i dont really have any complaints
 
DoctorDiff is the way to go. He’s not the cheapest, but you get better quality parts and great customer service.
 
I did not use a kit, I sourced all my stuff separately and was able to get free shipping on it all and saved $250 to $300 dollars and that included buying drilled and slotted rotors out of Detroit, do research on small parts if you do this because sometimes O'Reilly or auto zone is cheaper or the same and you don't have to wait. Although I know getting free shipping to Hawaii is not always available, Tracey

IMG_2107.JPG


IMG_2108.JPG


IMG_2120.JPG


IMG_2121.JPG


IMG_2122.JPG
 
I converted my 68 to the newer calipers. What brake hose should I use?
 
I converted my 68 to the newer calipers. What brake hose should I use?

If the calipers are to the rear you’ll want ‘69 Camaro disk brake hoses. If they’re to the front 73+ A-body hoses should be fine. But be aware 73+ calipers mounted to the front on a 68-72 A can interfere with a front sway bar.
 
If the calipers are to the rear you’ll want ‘69 Camaro disk brake hoses. If they’re to the front 73+ A-body hoses should be fine. But be aware 73+ calipers mounted to the front on a 68-72 A can interfere with a front sway bar.
Yes I do have them to the rear. Thanks for the info.
 
I did not use a kit, I sourced all my stuff separately and was able to get free shipping on it all and saved $250 to $300 dollars and that included buying drilled and slotted rotors out of Detroit, do research on small parts if you do this because sometimes O'Reilly or auto zone is cheaper or the same and you don't have to wait. Although I know getting free shipping to Hawaii is not always available, Tracey

So you bought the a arms etc from Orielly's? It's not always free shipping, but if I order it in store, its much cheaper shipping for certain. In this case, I would be asking for help in a parts list.
 
Last edited:
This has been a great post. I am researching doing this to my 69 Dart gts. A lot of great tips here. I have a question or 2 - I’m running 235/60/14 Year One rally 4inch bolt all around. I see some of these kits say they won’t fit Year One rally 14inch, others say the wheel needs to be 13.25 id to fit, and a youtube video went thru the whole conversion then said you have to have 14 inch wheels that are actually oem from a 14inch disc brake car, and another says that...”This is the largest OEM-style brake package that fits 14" disc brake spec wheels”. So, has anyone here actually had 14inch year one rally that they were able to keep the small bolt pattern? Thanks
 
This has been a great post. I am researching doing this to my 69 Dart gts. A lot of great tips here. I have a question or 2 - I’m running 235/60/14 Year One rally 4inch bolt all around. I see some of these kits say they won’t fit Year One rally 14inch, others say the wheel needs to be 13.25 id to fit, and a youtube video went thru the whole conversion then said you have to have 14 inch wheels that are actually oem from a 14inch disc brake car, and another says that...”This is the largest OEM-style brake package that fits 14" disc brake spec wheels”. So, has anyone here actually had 14inch year one rally that they were able to keep the small bolt pattern? Thanks

If you want to keep your SBP 14" Rallyes, your best bet is to probably convert to a factory Kelsey-Hayes four-piston system. From time to time, you'll find them for sale in this section:
Mopar Brakes, Steering, Suspension, Tires & Wheels For Sale | For A Bodies Only Mopar Forum
 
This has been a great post. I am researching doing this to my 69 Dart gts. A lot of great tips here. I have a question or 2 - I’m running 235/60/14 Year One rally 4inch bolt all around. I see some of these kits say they won’t fit Year One rally 14inch, others say the wheel needs to be 13.25 id to fit, and a youtube video went thru the whole conversion then said you have to have 14 inch wheels that are actually oem from a 14inch disc brake car, and another says that...”This is the largest OEM-style brake package that fits 14" disc brake spec wheels”. So, has anyone here actually had 14inch year one rally that they were able to keep the small bolt pattern? Thanks

SixgunSal,

I put SSBC front discs on my '71 Dart GT about 15 years ago. I chose SSBC because of the small bolt pattern (the kit is dual pattern) as my car has the factory installed A-body, sbp, 8 3/4", 741, 3.23:1 sure-grip rear end.

The factory 14" X 5 1/2" Rallye wheels fit perfectly. The factory 14" X 5 1/2" steel wheels DO NOT fit.

DSCN8771-cropped.jpg
 
Hey Bruce, great idea, now I am going to be doing a similar swap, but going to use a disc brake sbp from 68 cuda to my 69 cuda. I shoulda asked the guy about upper control arms. I will have to get those. As well I may need the proportioning valve. I planned on using a master cyl and booster from another drum brake car, but I think I may need a different master cyl.
You should be able to swap everything straight over. My understanding is that you need a different master cylinder because there is a valve at the port that keeps residual pressure needed on drum brakes to keep the cups sealed in the wheel cylinder. You don't want this residual pressure on the discs because this and will cause your pads to always have pressure. The proportioning valve is different. You can just ad an inline adjustable valve in the line going to the rear drum brakes. I have my 69 Cuda almost done and it has front drum brakes which I will leave this as since it is a number matching car. My 67 notch back had 9 inch drums and I had found a 1967 formula S 273 with the 4 piston Caliper factory setup and swapped the entire suspension to my 67 that had 9 inch drums. I also swapped the rear diff with 10 inch drums. I drove this car without modification to the proportioning valve and it never seemed to have a problem stopping but that was years ago and I plan to install a new oem type proportioning valve. I have a book I found a few years ago entitled "Performance Handling for classic Mopars" by Tom Condran. "Updating Suspensions and brakes with Factory Parts and your own tools". I don't know if this is still available but it is GOOD. Explains everything including being careful because some suspension parts will bolt up but could change the steering Geometry. Published by Faster Forge & Press, San Bruno, CA additional copies ACME MAIL ORDER P.O. Box 282612, San Francisco CA 94128-2612. I highly recommend it. If you cant find a copy I can look up your questions. A little rusty on suspension, been years since I did my 67 front suspension which I am going to rebuild again, This time I am using the offset upper control arm bushings for increased Neg Camber for better handling along with polyurethane bushings. another note is you swap out the tie rods with the larger size. The taper is the same just the threaded ends are larger so you have to replace the sleeves. I will have to look at my parts or find it in the above book.
 
Last edited:
Good thread .
I aquired a 1969 barracuda with BBP. setup with discs from a 1973 Dodge dart (I beleive ). It came with 15 inch rims and now has P215 R15 95H tires which touch the fenders in a turn . I beleive this is what caused the previous owner to crash the car and led to my aquisition of the car . The car would originally had 14 inch bias ply 70's . I either put narrower or lower profile tires, create an abnormal lift, customize or roll the fender back (unless something else is incorrect??). If there is a post that resolves this problem could someone direct me to it . I don't want to start a thread if the info is out there already and I beleive someone must have tried this before. Any advice much appreciated . Thanks
 
Richard are you sure you’re not missing something about the tire measurement that’s on it? If it truly is a 215/95/15 that shows a 31” diameter tire which is wayyyy to big for our cars I think. No wonder it’s rubbing the fender. Double check that tire size as most of us don’t run anything that big.
Tire Size Calculator

that said there could be many different reasons for the rub such as strut rod configuration, wheel offset and fender brace length if it has them.

I think you should start a thread with more info for sure.
 
Richard are you sure you’re not missing something about the tire measurement that’s on it? If it truly is a 215/95/15 that shows a 31” diameter tire which is wayyyy to big for our cars I think. No wonder it’s rubbing the fender. Double check that tire size as most of us don’t run anything that big.
Tire Size Calculator
I am sure you are correct and I will get smaller tires on it
Thanks
that said there could be many different reasons for the rub such as strut rod configuration, wheel offset and fender brace length if it has them.

I think you should start a thread with more info for sure.
 
Can you post a picture of the tire? 95h sounds like a speed rating. I'm sure it's not a 95 series tire.
 
Just measured the wheel diameter. It's about 26.5 inchs however its almost 9 inches wide . I think the width is the critical problem . I have different tires I will mount shortly and advise. Thanks.
 
Just measured the wheel diameter. It's about 26.5 inchs however its almost 9 inches wide . I think the width is the critical problem . I have different tires I will mount shortly and advise. Thanks.
215/65r15.
 
I didnt read all these posts , are those ur front wheels ? how wide are they ?
Those are my front wheels. I started a thread on the NEW steering and suspension Forum . These rims appear to be 7 inches wide( I haven't got a good caliper so I am guestimating ). I beleive the diameter should read 25.5 inches. According to other responses on the steering and suspension forum this is not a simple conversion.
 
Those are my front wheels. I started a thread on the NEW steering and suspension Forum . These rims appear to be 7 inches wide( I haven't got a good caliper so I am guestimating ). I beleive the diameter should read 25.5 inches. According to other responses on the steering and suspension forum this is not a simple conversion.
I now have 8.5`s on the back of my car, would like to have some fronts to match , but 7'' is the narrowest ones they made , maybe 6'' , but I dont want that much weight up there .
 
Anyone have this issue? The spindle bolt is hitting the control arm where the sway bar bracket is welded. Won’t turn near far enough.
45AC3FFD-816C-474C-B0FB-BCAD9E38A8E6.jpeg
AA9984A6-2807-4FA8-95AE-D81E5D273F43.jpeg
C27C3070-3E15-43C2-A94F-3453B0BB014E.jpeg
 
-
Back
Top