disc brake conversion

That sounds kinda odd to me. You said the draglink now hits. But you didn't change either the pitman or idler arm correct. Sounds like this has nothing to do with the swap just maybe a coincidence. Did by chance the get jacked up by the draglink along with the k-member? The spindle dimensions are the same along with a-arm. The only thing that's different is the ball joint size. Either that or your motor mount went ka ka, and the motor has dropped some.