If you look at the front cover next to lower right corner has a size I’d cast in. This is my 80 gmc k3500 Dana 60 single wheel, all my brakes came from rock auto
I am also a gbody fan 87 grand national with c6 zo6 brakes and Hotchkis control arms, making it a GNX as I will not spend that much money on a regal. My long term project is a 67 impala SS pro street with 6.2ls mirror image turbos and air ride.
Had one for a few years it is great.
It is a hydraulic flaring tool, brake line, gm fuel line. You can get dies to do 37 deg. fittings and tranny lines. definitely a cool tool!!!