OK, sorry for maybe asking what might be a stupid question, but why would you swap drums for drums? Just use the very cheap Scarebird conversion to cheaply and easily add disc brakes to your car and make it 4.5 pattern at the same time. It's the all-around win solution here. The only reason I can think of to do what you're trying to do is if you can get a basically free or almost free swap with someone else's discarded parts. But even then, for the few hundred that the Scarebird conversion would cost you, why would you not want discs?
