disk brake conversion Q's

-
tensec340

tensec340

The LEGEND
Joined
Jan 10, 2008
Messages
506
Reaction score
21
Location
Long Beach,L.I., NY
looking to do a 9" drum to disk conv on my 69 Dart, been doing allot of research and getting a little confused.
I'm not sure on the a arms/ball joints.
do the kits use my old ones or do I need another years or there a arms ?
Or if I go with a ,say 73 duster do I use my a arms or the ones from the donor car?
Prefer going with after market kit.

Thanks,Tim
 
Depends on the kit you use if you can reuse you control arms and ball joints but your better off upgrading. The 9" drums used a small ball joint that many feel isnt the safest set up.

The 73+ disc require you to use the 73+ control arms and ball joints.
 
Yep, I'm unsure also.....if I put 73 disc brakes on my 68 do I need to change both upper and lower control arms or just the upper control arms? I know I have to go the big bolt pattern.
 
Just the uppers arms and upper and lower ball joints need to be changed to 73 - 76 PARTS
 
The lower ball joint is the same.

Only need to swap the upper arms on 72 down cars to the 73+ BBJ uppers.

Everything else is a direct bolt up including tie rod ends.
 
I thought the lower bjs were different ? Did they change at all from 62 to 76 ? ?
 
Adam,
You are correct,the 73-76 uses bigger upper and lower ball joints,however you can still use the early lower control arms.

Anybody doing performance upgrades such as disc brakes,rear ends,engine swaps,etc should have this book.Pretty much has all the answers.

Picture 680.jpg
 
I got ball joints and the control arm attachemnts confused.

Yes the ball joint is different, they carry different part numbers through moog.

The late ball joint will bolt into the earlier control arm.

Thanks for the correction Johnny and Adam!
 
crackedback said:
I got ball joints and the control arm attachemnts confused.

Yes the ball joint is different, they carry different part numbers through moog.

The late ball joint will bolt into the earlier control arm.

Thanks for the correction Johnny and Adam!
Click to expand...

No worries!!

Things like this is why this book is so valuable.
For example.Although the late (bigger ball joint) will work with the early lower control arm a little grinding may be necessary on the steering stops of the bigger ball joints,because the early and late control arms are shaped differently in this area.

also the early sway bar will hit the 73-76 calipers.You can fix this by swapping the spindles to opposite sides,and running the calipers on the back of the spindles.
 
Johnny Dart said:
No worries!!

Things like this is why this book is so valuable.
For example.Although the late (bigger ball joint) will work with the early lower control arm a little grinding may be necessary on the steering stops of the bigger ball joints,because the early and late control arms are shaped differently in this area.

also the early sway bar will hit the 73-76 calipers.You can fix this by swapping the spindles to opposite sides,and running the calipers on the back of the spindles.
Click to expand...

Funny thing... I have that book on my desk!

Another way to avoid the sway bar interference is to shorten the link at the control arm attachment point.
 
crackedback said:
Funny thing... I have that book on my desk!

Another way to avoid the sway bar interference is to shorten the link at the control arm attachment point.
Click to expand...


And another way is to install a 73-76 k-frame/sway bar...eesh :sad1:
 
Concerning the safety & smaller lower ball joints - most feel that the safety gained is due to the larger attaching bolts between the lower ball joint arm and the spindle. I forget the size difference, but it is much stronger.

I am converting mine right now to the 73-76 and I can't wait to have good brakes instead of the "every stop is a panic stop" 9" drums.

Good luck tensec340.
 
"9" panic stops"

Oh yes,remember those !!!!! Whhhhhhooooo-Neeeeelllllyyyyyyyyy !!!!!!
 
I've been told that the 73-76 disc conversion from 9" drums actually sets the wheels further apart. (widens the track by a bit) Can anyone confirm this? If so, how much wider is it from flange to flange? Unfortunately I didn't get my stock drum to drum measurement prior to pulling them. Now I want to order up some 4-1/2 BP wheels but if the width is different I'll need to take that into account.
 
I have a '73-'76 sway bar on my '72 k-member and it fit fine, you just need the '73-'76 lower control arms to match.

Chuck
 
I swapped 10" drums on a 69 dart to a master power 4 wheel disc kit and it cut the stopping distance in half!
 
Theres a bit here on this forum on drum to disk swaps. I'm going from 9 inch drum to factory small disc. I was going to do a late B body swap with the larger 11 inch rotors, but a good fella needed them.

I'm still not exactly sure on everything. Since I also want to (Sooner or later) add a anti roll bar to the car on the front and rear. The '74 Duster didn't come with a sway bar with the 9' drums. I'm sure this isn't a big problem, it's just lack of knowing at this point before actually doing it. (Cash is another issue for the moment.)

Later on, this could change. A serious system for a quick car that for me, and a few others here, that would see enuff street duty to warrant a system for a 3200lbs. car or so is needed. I have no real clue to this, so I looked around for a few places that should since thats there biz. Heres what I found.


Advertised in Mopar Muscle;


http://ecihotrodbrakes.com/ ,
http://magnumforce.com/ ,
http://justsuspension.com/ ,
http://reillymotorsports.com/store/home.php ,
http://www.p-s-t.com/pc-3845-140-dodge-dart-1964-72.aspx , http://www.moserengineering.com/Pages/Brakes/disc.html ,
http://www.mpbrakes.com/products/search-results.cfm

Parts and a tech number at the bottom of the page; http://www.firmfeel.com/b.htm ,

Food for thought, a full K swap out for a tube K.; http://capautoproducts.com/

I think a full kit, be it a total K change out of just one that bolts to factory parts is a great thing. Just so long as they the sellers know whats what and what can and can not be done or what needs to be changed out for there kit and what upgrade or swapable parts are OK to do with said kits.
 
ALL A-body Lower Control Arms WILL interchange from 63-76. 9" drums use a smaller lower ball joint. 62-72 10" drums and K-H disks use the larger lower ball joint. 73-76 disks use a larger upper ball joint, same as B-cars. To convert to later 73-76 disks you need the associated spindles and UCA's.

To convert a 74 drum car (SBP) to K-H disks, you just need spindles, lower ball joints and brakes. Your control arms will work. To fit an OEM style sway bar to a 73-76 K-member, you will need 73-76 "low" tabbed LCA's or will need to fab and weld on tabs.
 
I finally got a chance to measure the stock distance from flange to flange on my '64 Valiant with original 9" drums and the '64 Barracuda with the 73 and later disks. The discs measure 5/8" wider than the 9" drums. (5/16" per side)
 
You must log in or register to reply here.
-

Back
Top