there are a lot of ways to do things
i did mine while driving it. Well not exactly, but I daily it and upgraded a part or two in the evening after work and then drove it the next day
u can start small and cheap if you want, like I did and still have (for the most part).
V8 fox body front spindles are a must. 4 cylinder spindles won't take a V8 strut without machining, and exactly nobody makes any decent struts for 4 cylinder spindles (that I knows of). V8 sway bars front and rear if you don't already have them. Springs, I used
BBK's because they were already on the car (lowering springs--they are stiffer than I like but work decently well for a street car). Blue Tokico dampers on all 4 corners, no quads (original 4 cyl car and still is 4 cyl). Sway bar bushings are a must (poly). Subframe connectors are a must. Full length weld in of course and nice to have the "seat braces". Just the SFC's make the car feel "tighter". I have done several front
control arms; started with the worn out stockers and the ball joints started getting loose. Replaced them with something I found on ebay, bolt-in tubular with spring seats and poly bushings. I do not recommend poly bushings on the front
control arms, at least if you use the stock location springs (coil over different story). They are just too rough. You feel every crack in the pavement but they don't deflect much in cornering. Don't forget rear
control arms either, they also make a difference when coming from worn out stockers. The new edge Mustangs had slightly stiffer bushings in their UCAs so if you're really cheap like me, pick up a set from a JY V6 car. Steering? Cobra or at least an SN95 rack. The SN rack isn't "that" much different in terms of "feel". If you can't find a cobra rack, just ask for a v6 rack. With that you will also want poly rack bushings and the MM "hybrid" steering shaft is a MUST HAVE. It is really a nice piece. It costs but it is NICE (and safe). Of course caster-
camber plates are a must have on any fox body. Slot the strut tower holes if need be to get as much caster as you can.
alignment. 1.0-1.2 deg camber is ok. you can go up to about 1.5 but beyond that you're looking at tire wear and tramlining. Tramlining is going to be an issue even at 1.2. About 1/16" toe in is fine. You can adjust for your liking, I like it closer to zero. Caster, as much as you can get. With stock
control arms you can't get enough so just shove them all the way back and tighten them up. If you find that the car pulls to one side consistently, remove a little caster from that side to take the pull away. U can do alignment at home and it's very close to what laser machines "say", if you do it correctly, but you need good flat concrete.
At that point you have a Mustang that handles decent, with tires that will bite of course. It will not be a race car but the investment is little. I drive mine. A lot. The roads that I frequent are hilly country highways, speed limit 55 but you're lucky to find a straight stretch that you can get much more than 50 on. Spirited but not aggressive. If I am driving and forget about the 15mph switchback, I want the confidence to know that if I'm at 45, I can get around it without too much trouble (as long as there's not any animals or road debris which has been often lately)
Brakes. If you use the stock front V8 discs, pick up a set of Hawk pads, SS hoses, and a set of MM's "performance" drum brake shoes if you still have drums. That setup feels better than my 01 cobra brakes that're on my 92 GT. The rear drums aren't ideal for any kind of racing but if you're cheap like me, they will do just fine. Predictable.
IF you want to make a big difference toss on MM's
panhard bar, and eliminate one of the UCA's for a "poor mans 3 link". Huge difference. Unfortunately it may not clear 3" exhaust which I have, and I found out that hard way. I need a tailpipe so I sold the other stuff and stuck with a stock rear
suspension which is better than leaf springs but not by much.
my setup has under $600 total tied up in it and most of that was struts. Everything else was bought used or came with the car. I'm happy with it.
also remember that if you have a 4 cyl car the front lower control arm mounting points are about 3/4" narrower than V8 K member is, in other words the total track width of the front tires is about an inch or so narrower than v8 cars were...so....you can use SN95
lower control arms and get the width back, without changing the k-member and improving the roll center a little.