Looks like we have different ideas about what works and what doesn't, and that's fine. You are right about me having never driven a rack-equipped vintage Mustang. But after seeing how fast non-rack Mustangs go around Laguna Seca a few years ago at the Monterey Hstoric races, I seriously doubt they would have gone one iota faster witha rack. I kept the power steering because to works fine without even one leak, and it'll turn MUCH tighter than my '88 GT with a rack. Anothet thing to consider is, I built my fastback to drive, and drive it I will. I plan to make the HotRod Power Tour next year, in fact. Now I ask you, what happens when that custom rack has a problem (don't say they never fail, everything fails and always at the worst time) in Upper Nowhere, Kansas? Can you buy parts for it at NAPA?
As far as the rear swaybar upsetting the balance, I know that's a common myth, but I say that anyone who doesn't think they help has never driven one. Hmmm, where have I heard that before? Seriously, stock vintage Mustangs have no balance, so how could you upset it? I've used rear sway bars on street and race cars for years , and have yet to have one even come close to being a problem. My wife's '69 Corvette came stock with one, as did my '88 GT and my Suburban, and I while I don't corner hard in the Suburban, a promise you the Corvette and the GT have seen HARD cornering and neither has swapped ends yet. Try one, I promise you'll be happier than without a rear sway bar. I have an adjustable 3/4" bar from Branda's on mine and it made the car such a pleasure to drive. The key in desiging any modifications to any car is to think for yourself, think evevrything through and don't buy anything just because someone says it's the only way to go. There are lots of ways to happiness and even more ways to misery in chassis design.