Balljoint Questions for disc swap? HELP!

[swingn340]

69 dart, LCA to 74 A disc spindal. do i use the 69 or the 74 lower balljoint? some of the info says to use the newer BJ but is the hole in the LCA the same size. or is the holes in the BJ different from the mounting holes on the spindal? any help would be great. Thanks.

 

[C130 Chief]

Use whatever ball joint matches your spindles.

 

[70DartMike]

You can keep the 69 LCA and use the 74 spindle, meaning you will still use the same ball joint for a 69. The UCA will have to be changed to the bigger ball joint style, meaning you will need to take the one from the 74 and use it.

 

[swingn340]

So i still have the same question 1 for use the old BJ and 1 for use the newer one. If the newer one will work ill use it. Its only half the price as the older one.

 

[abodyjoe]

you use the 74 ball joint on your 69 lower control arm. it will bolt right on with no modification.

 

[abodyjoe]

A-BODY DISC BRAKE CONVERSION

It's helpful to know the various chassis designations in order to find the correct parts.
Please refer to the Chassis Style page for more info

1. Upper Control Arms, from 1973-1976 A-Body Disc Brake Car. (single Piston Caliper only) The upper control arms are needed because the A-bodies were upgraded to the bigger B-body balljoints in 73, which means you need the later a-body arms to get the bigger balljoint. You can see the balljoint differences on the Steering Linkage Page

2. Spindles from 73-up A,B,E,F,J,M,R chassis disk brake car. Drum spindles don't work.
Note - the B,F,J,M,R spindle does have differences... Read A vs. B spindles for more info
3. Rotors and calipers - A-body rotors were 11" and were also used on many other cars. Some 77-79 B and 79-81 R bodies used an 11.75" rotor. Both rotors fit all spindles above. You do however need to use the caliper bracket that matches the rotor diameter. There are pin-type calipers and sliding calipers. The correct one must be used with the corresponding bracket. Most likely you'll find all your parts together on one car. The less-desirable pin-type calipers were used on the E-bodies, while most other cars had the slider style calipers.
4. Divider block and prop valve from a donor disc brake car.
5. New Front Brake Hoses (Rubber)
6. New Brake Pads & Bearings (you must know what make, model and year of the donor car)
7. New Master Cylinder, Disc & drum, use 73-76 A-Body, with or w/o power brakes
8. 4.5" bolt pattern front wheels.
9. New Upper Control Arm Bushings recommended
10. 73-76 Lower Ball Joints are necessary. The stock lower control arms can be retained.
11. From the donor car, remove the (2) lines that are attached to the master cylinder, and use them on
your car. it just easier to use these lines than to bend up your existing ones to work.

http://www.bigblockdart.com/techpages/dbconversion.shtml




.

 

[abodyjoe]

http://www.bigblockdart.com/techpages/linkage.shtml

Another item of interest is the difference in the lower balljoints. You can see the obvious increase in size of the 73-up balljoint. Also note the addition of the cast-in steering stop. You might notice that the casting is different, but stud itself is the same. This is why, although the late balljoint is needed for a brake conversion, the early lower control arm can stay.

This is a comparison between the early and late upper balljoints....Major difference.
To tell which one you have, the early balljoint has wrench flats that measure 1 3/4". The late balljoint wrench flats measure 1 7/8. You can also measure the studs to know what you have. Early ones are 7/16" threads and late ones are 9/16" threads. The early upper balljoint can only be used in early applications, so for instance, if you know you have the early upper joint, then to do the late disk conversion, you'll know you need all the parts from a late car. If you find you already have the late upper balljoint, then all you need is a disk spindle.

 

[mopardude318]

Although I already know this, Joe you have posted nice info for someone who doesn't know.

 

[MR JIM]

Very nice pictures and info..Good work!!!!

 

[abodyjoe]

its all off the BBD tech pages.

 

[swingn340]

Thanks A body joe. I was a little unclear about this but thats what i thought. Just didnt want to buy the wrong ones and the newer ones are half the price:-D

 

[Robbie2734]

http://www.bigblockdart.com/techpages/linkage.shtml

I used the newer ones on my conversion. The bump stops cut my turning radius a lot. I took the grinder to them and all is good..