Have'nt heard that before in all of the disc brake swap stuff I have been reading. Were you using the correct caliper? Late B-bodies had the brake line fitting in a different spot compared to all of the other pin type calipers.
They were 74 B body pin calipers. None of the pics I've seen show a different location.
I had a set of slider brackets and new calipers so I just swapped them out.
