Sorreeeee. Not here much myself actually, so forgot my manners.

Some imported 3rd party equipment (Willwood) will use American threads. Difficulties generally come with anti-confusion design. On non-ABS systems Ford fit a Pressure Control/limit Valve in rear brake lines or directly into the master cylinders (some early ABS systems had them externally). One end is usually M12x1. Makes sure they are the right way around, but a pain if you want to eliminate them.

See the KA thread in this section.

Martin