BB A-body fenderwell headers and Master cylinder brake line help

Guys does anyone here know off hand what size thread and thread pitch the flair nuts are that go into the master cylinder and also on the other end of those 2 MC lines where they go into the proportioning valve? Im at work at the moment so I don't have them with me but have a chance to get some new ones if I knew the correct size and pitch of the threads..
Why dont you just cut the ones off the old lines and put them on the new lines then put new flairs on the lines?