When you get your TB bored to say 56mm, where do you get the butterfly to replace the 52mm one?

Those that get theirs bored send the whole unit out and they (like ARD) will bore it out and make a new butterfly, those of us that bored it ourselves must also get a new one made like a machine shop etc.. or just do the jeep tb mod its a 60mm one

1998 dodge avenger 4 cyl AT
Mods are:
Not enough