Brake lines to MS ?

1976 EB with factory power brakes .
I have a silly question about the front brake lines where they bolt to the master cly . I know that the large reservoir is for the front disc brakes but which line coming off of the powerbrake distribution block goes to the front brakes . One line has a larger fitting and one is smaller . The mastercly has a small and large hole . But when I bleed the brakes it seemed that I had them backwards . I feel stupid with as many old Mustangs that I have restored I dont know this but I have never had one with power brakes . ?:?

The combination block on the frame rail is front to front and rear to rear, not oppsite like the MC. The line front the large reservoir (rear port) on the MC goes to the vertical inlet port in front of the brake balance switch. The angled port in front of that is the outlet port for the front brakes.