Pst suspension parts exchange needed?

[snapetwo]

So I swapped my 73 k member, s6 w disc brakes for a 71 k, v8 w drum.
Only thing I see needing changed is the idler arm. The rest of parts arent bolted to k member.
Contacted Pst and was informed now my ball joints both upper and lower will not work now.

Can anyone tell me why?
From what I see, I don't see any issues...

Keep in mind, all I swapped was the k. Car is still disc.
If I went to drum, I could see needing ball joints.

 

[FISHBREATH]

My 'Cuda is not of that vintage, but I seem to recall reading that the location of the steering linkage or sway bar changed location. I can't remember. Somebody with more knowledge will certainly soon figure it out for you.

 

[snapetwo]

Thanks, I know I've mocked it all up. And it all looks like it works. But....

 

[Darter6]

If your car was a 9'' drum brake /6 they may be thinking that you are going to disc brake spindles that require the bigger ball joints. Just a thought...

 

[AdamR]

If all you changed was the K frame and your still using the disc brake control arms and spindles your ball joints are fine.

 

[snapetwo]

Thanks guys. Kinda what I was thinking. All I need to change is idler arm, cuz the one I have doesn't fit.