This past spring I rebuilt the front end of my '59 1/2 ton, got the bushings, pivot bolt, etc. from LMC too, but everything on mine went together easy as pie. The threads matched up, no filing, drilling, and so on needed.
I don't think I would drill it out. I'll call LMC and talk to somebody there, laying out what you have going on, what part numbers you have in hand, that sort of thing, good luck.
