1972 Duster...is this a good deal?
...my '75 had drums up front....
You're right, only the V8 cars got standard disks in '73, the /6 cars could still have come with drum brakes. Mine did have disks from the factory though. Disk brakes became standard on all of them after 1/1/76.
Sounds like the car in question may have been upgraded to disks already though.
And I forgot to mention it before, but there's absolutely, positively, no way I would run a 383 with /6 bars on the street. That may be fine for a drag car, but it's not a good idea on a street car. Too many crazy drivers out there to sacrifice that much handling. Heck, I don't think /6 bars are a good idea on the street even with a /6.