I tore out all my old crusty brakes lines except the line connecting the two rear drums together. I have a brand new Aerospace master cylinder and new stock style proportioning valve from Kirbans. Question is, what was the factory line orientation? There's two ports on the master cylinder, the two lines coming off both front calipers, and I think the prop valve has 3 ports. Sorry this is my first time doing such a job and don't mean to sound dumb. Thanks.