What type of flare and brake line size

I found a 4 way brake union that is used in the booster delete kit that I want to use for a race car of a different make. For the life of me I cannot tell what type of flare is used or what size it is. I did a double inverted flare with 3/16 line and the flare nut would bottom out before it got tight. Below are pics of the fitting and then the flare that they say the S14 uses. What do I need to use and do to make this flare.

The 4 way union is a 10m x 1. Flare nuts are correct. These lines are going a short run from the master cylinder to the 4 way.

Thanks in advance.