You can use 1/4" lines. I have a 10 bolt Camaro with 12 disc brakes and I am using 3/16 lines. http://good-times.webshots.com/photo/2540282850099708909YZvPCm
I use a Snap-on flaring tool but you can find them at Northern Tool or Harbor Crap freight.
BTW the 12 bolt you are talking about is a later Camaro/Firebird rear. The 10 or 12 will fit depending on what year truck you have.


~Jim