My mechanic and I just fitted a new brake booster and steering link to join the steering shaft back to the steering box.(Borgeson flexible couplings known as ‘rag joints’) A word of advice to anyone running the rag type of link, be careful if brake fluid ever leaks on that, it may cause it to weaken and break, a particularly bad problem if you notice some play in the steering wheel, meaning a circlip has let go, eventually it may let go completely and because the link and the circlip let go together, you'll have no steering at all, as your steering wheel comes out of the steering column. In my case I could not steer my car to assist it onto the tow truck and had two people moving the wheels with hands on tyres to get into the mechanics premises. Fortunately the steering had let go in Ultratunes' workshop while the tranny was out of the car and I or my wife are not dead.
I'm waiting for my c4 to come back from the reconditioning and it's another step forward again.
I am not sure if all Mustangs will have the steering column part of the problem or if it was a fault of the later model ford steering column I fitted during the Right Hand Conversion? Just be careful please and remember some of those round circle steering linkages will be approaching 50 years old now and your life is depending on them. Because the neoprene (red replacement part) resists the effect of exposure to brake fluid I replaced it with that. The supplier told me though, that the neoprene does not like to take too much heat, a problem if it is too close to your extractors.
Mustangs do certainly have a few traps for young players.