There are a few threads around about that, including that block on the 91 and 92's.
One of my brake line sets has a nice block from some company, but I have never been able to find it again.
I've seen others use a brass block (kinda big).
I've made one set of brake lines for Cybergasm and I took the factory brake line, cut the hard part of the flex line flush with the block, tapped it for 1/8" npt and then put on a 1/8" npt to brake line fitting. I know your not supposed to use npt on brake lines, but I saw it done on other vehicles and the speed shop I go to also does it. Heck, Earles sells it (division of holley that makes brake hoses).
So far, its holding up for him and I'd guess its upwards of 2 years old by now.
~Mark