On the 73 -76 A body cars there is NO difference in UCA's if the car is equipped with disc brakes, or 10 inch Drum brakes.
They are all the same thing. No difference to them at all.
They all use the big ball joint.
There are some early, odd ball, 6 cylinder, drum brake, 73 A body cars, that came off the assembly line with 9 inch drum brakes.
Those cars had small ball joint upper control arms.
Chances, coming across one of those cars in this day and age, is pretty slim, but some members report that they have one, or at one time had one.
In my 30 years of professional wrenching, and going to the wrecking yards, i have only came across two, or three, of these stripped down models.
And another thing to clear up is if you have Kelsey Hayes, 4 piston disc brakes, on a 65-72 A body car, those A body's used the Small ball joint UCA.
Those 62-72 A body's all used the same UCA wether it was Drum brake, or Disc brake equipped.
Large ball joint UCA's started on the 73 A bodys, with disc brakes, or 10 inch drum brakes.
You use 73-76 A body lower ball joints when doing the brake conversion.
Lower ball joints are the same thing for disc brakes, and 10 inch drum brakes, on the 73-76 cars.
