One thing that never gets mentioned... If you file the bolt hole to correct the drag link side to side you've created a point of motion, it will find a way to loosen & move... So to fix it when you are assembling the idler put a semi-large flat washer on before the nut & when you have the drag link level & things are tight put a few tack weld on the washer to the K frame...
Seems pretty straight forward, I assume I would have to make shims?
No, standard alignment shims work just fine...