68 Lark Disc to Drum fit

I have a 68 Skylark with drums and I bought a disc brake system that was on a 71 Chevelle. I put in new upper and lower ball joints and when I went to put the knuckle on the ball joint stem was to big and wouldn't let the knuckle seat all the way down. Its not by much so my question is do I need to buy different ball joints or do I machine out the knuckle bracket?

Thanks

 

u should purchase the correct ball joint for your car.

 

The old ball joint that was in to began with don't fit the bracket either. The hole is smaller that the one on the drums. ball joint looks to be the correct on

 

AFAIK, all parts for the front end for stock GM A-bodies are the same. I pulled the A-arms from a '72 Le Mans with disc brakes and installed them directly onto my Skylark. I had rebuilt the entire front end and then realized that the Le Mans was too much of a rust bucket to continue the restoration. Note that they were single-piston calipers, so I was able to use the original 14" sport wheels.

 

Every single GM A Body from 1964 - 1972 -- Every Buick Special & Skylark, Every Chevelle, Malibu, El Camino,
Every Olds Cutlass, F85, 442, and every Pontiac GTO / Tempest/ Lemans

use the same upper & lower Ball Joints;
10195 TRW = K5108 Moog === Upper Ball Joints
10197 TRW = K5103 Moog === Lower Ball Joints

while other Front End components are different, the Ball Joints are Identical, as indicated....

 

i thought some of the early '70 chevelles had oval ball joints.?

 

Now that you mention it, I do recall that some BBC suspensions have oval bushings in the lower A-Arms.