The setup shown on the picture I posted of my car, is correct. The
oil cooler is female pipe thread. Then a blue hard 90, pipe into the cooler, and -12 on the hose side. Coming off that, it's an AN style screw together fitting. The flats of the fitting are completely flat, as opposed to what some restorers use on these cars, where the wrench flats have a rounded edge to them. Then the hose socket is short, with the small neck and sharp transision to the neck, just like in my pic, as opposed to the long tapered socket that some people use. The fitting is actually a -12 to -10 "jump" fitting. The nut site is -12 and the socket side is -10, but it takes an odd hose that's kind of in between the two.
I spent A LOT of time into the research of this, talking to many people who are knowledgable in this stuff. Some are fellow board members here, some are original car owners. I also have great reference pics of lots of original cars.
The hardest part of finding the truth behind the correctness of these cars, is that most of them have been modified over the years. Even cars that are touted as very original, have had most of the important detail parts changed over the years. Comp cars especially are usually VERY altered from as they came from Shelby, even if it's just from routine racing replacements of stock parts.
BTW, we are putting together a new motor for my brother's Mustang, and using a ManOWar block. This thing is insane. The only thing that sucks is making the
oil pan fit the mains in the rear!