UCA ball joint interchange?

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Mojoe9955

Mojoe9955

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Can you use the later A body big ball joint in an early A body upper control arm. I see many posts stating there is a difference in the arms, but other than the ball joint issue I'm unable to figure out what it is.
It seems they are the same other than the ball joint socket is possibly bigger?
While looking for the ball joints I've noticed the the early ones cost twice as much as the late ones.
 
The opening For the ball joint is small on the early A arms and the later ones accept the bigger ball joints. So to go to bigger ball joints you would need a set of later 73 up A arms.
 
I know they are "bigger" my question is, is the diameter of the ball joint where it screws into the control larger or is it the tapered shaft the goes into the steering knuckle larger? I ask be cause the car I have already had a disc brake conversion and I'm not sure what I have.
I ordered bushings so I can use the small ball joint in the bigger spindle as well as the small and big ball joint to on use dependingwhich control arms are on the car now
 
Mojoe9955 said:
I know they are "bigger" my question is, is the diameter of the ball joint where it screws into the control larger or is it the tapered shaft the goes into the steering knuckle larger? I ask be cause the car I have already had a disc brake conversion and I'm not sure what I have.
I ordered bushings so I can use the small ball joint in the bigger spindle as well as the small and big ball joint to on use dependingwhich control arms are on the car now
Click to expand...

Yes that’s what I posted above trust me you will need 73 A arms to use the bigger ball joint. The way to tell which ball joint you have is to measure the width across the flat where the ball joint socket fits. 1.906 small 2.125 big.
 
inertia said:
If you have new joints in the smaller Arm, this adapter will allow use of small joint arms with big joint spindles, I think you are looking for this.

Mopar A-Body Upper Ball Joint Tapered Adapter
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Click to expand...
Yes I have them and I ordered the big and small ball joints, just in case.
I have another car that I'm going to put front disc's and rebuild the front end. I have all the parts for that with the exception of UCA's so I'll tailor my part search according to what I have left over.
Thanks for the info.
 
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