best 5x4.5 disc conversion on my 1968 dart 2dr post

Whats your price range?
Stuff like a distribution block/proportioning valve and new lines will be needed with any swap.
You can spend a couple hundred-ish on an FMJ swap or several times that for the aftermarket "kits".
Personally I'd go with the FMJ.
Oh wait...I already did :D

Totally agree. The only problem now is finding the donors. It used to be you could just head down to PickNPull and grab an FMJ set up if you checked their website and got up early when a suitable donor came in. I get emails now when certain cars hit the yard, and I've only seen one suitable FMJ brake donor hit the yards around here so far this year. And California has it pretty decent for workable cars hitting the yard, most places the FMJ supply dried up awhile ago. I mean, they show up occasionally, but it used to be easy. DrDiff's kits aren't bad for price considering you get all new or rebuilt parts, even using almost everything straight out of the yard you'd still be spending at least a couple hundred bucks.