87 ball joints to a 66 control arm?

[Turtleman]

I'm wondering why I try to do things the hard why.
Most that convert to disk brakes just remove and replace the whole A-Frame, or buy a kit..
But I'm in the same process and I'm looking at this another way.
I have the whole front clip from a 87 as parts.. and I was going to move them onto a 66 C-10.
So I was thinking if someone who's done what I'm thinking might be able to answer a few questions.
Why cant I press the upper and lower ball joints out of the 66 control arms. Replace the ball joints with a 87 ball joint, add the 87 spindle and disk rotor.. and I'm good to go.
Do 87 ball joints fit into a 66 control arm?