I tried a couple different ways about getting disc brakes on my car.
The firstway: I put on 69 Camaro spindles. I put the Camaro spindles between My
Chevy II ball joints. I had to make a cone shaped spacer for the lower ball joint. The
Camaro spindle hole was larger than the Chevy II ball joint.
The car would align on the alignment machine ok and drive down the road straight,
but always had bump steer. After going over a bump or railroad tracks when the
front end lifted up, the wheels would toe in
or out, and when the car settled or came down, the tires would chirp and scuff.

  The second way: I ordered some  spindles from a company that sells disc brake
kits. Paid $200 US dollars for them. I examined them and found out they were
modified stock Chevy II spindles to accept Camaro/Chevelle rotors and backing
plates. Much money could be save by modifying your own Chevy II spindles. If .060
or metric equivalent were shaved off the mounting surface where the top bolt of the
old drum backing plate went on, 69-72 Nova//Chevelle 69Camaro caliper brackets
will bolt on the Chevy II spindles. Another hole for the bottom of the caliper bracket
may need to be drilled and tapped in the spindle, I can't remember for sure. Then the
rotors from the 69-72 Nova//Chevelle 69Camaro will fit just fine on the Chevy II
spindles. 62 Chevy II spindle  won't work. 63 up Chevy II need to be used. I forget
why the 62's won't work.  I know I don't have the best details because it was a long
time ago I converted the brakes to disc. My car drove much better with the ChevyII
spindles than the Camaro spindles.