Brake line flare nut thread size/part id help

[MK667]

Hi folks, so I have a 2004 FX4 4.0. I'm doing my rear brakes right now and I was trying to get the old driver side cylinder out and I just cannot get this brake line to budge. I've used penetrating oil and heat, and that worked on the passenger side. Also this nut that threads into the back of the cylinder is complete rounded. Time for new lines. The threads size on the cylinder is 3/8-24 and it's a 7/8 head on the nut. I have 2 questions. Do any of you know the thread size for the nut that screws into that block looking thing over the rear diff? Also, what is that part over the rear diff that driver and passenger side hard lines screw into called? If i have a name i can doing some more searching. Thanks in advance.

 

[Uncle Gump]

That is not a 7/8 wrench size.

Try brakel line distribution block.

I also believe the line nuts are the same size on bothe ends.