Well; that’s a good question. I have some “cargo” springs on the rear of the car, they are not too high, but are progressive in the spring rate, they doo have a tendency to wear thru the lower isolator/insulator cups, this is my second set of insulators on the same springs. I think they may do them for your boxtop as well. They are not too harsh, but firm.
I have tried the 4 cyl mustang front springs, because I had some laying around, they weren’t what I was looking for, so I went back to the v-8 springs. I don’t know what v-8 they came out of, if it was the mustang or Fairmont as they are supposed to be the same… and at the time I had so much mustang stuff laying around, I just labeled it v8 or v6 or 4 cyl.
I tried a set of used tokiko’s up front but they popped after a few months, didn’t really notice any difference, I thought it would as they came off a Cobra., that could also be due to the terrain I was driving on also, so I went to the ford shocks, they lasted quite a while, then one took a dump, I replaced it with one from Gabriel, because it was cheaper, it has lasted quite a while, now the l/s/f shock has shot its load, its gotta wait. Both rear shocks were from the AutoZone or sears store for a Fairmont/mustang, same shock??, they seemed ok, but both have pooped-out.
I would not recommend putting rear shocks off of a grand marquis or town car, because when you throw the anchor on really tight, the trunk lid tries to pass the hood ornament.
There is an assortment of sway bars available to play around with for frt and rear.
I don’t have much travel on my frt suspension, maybe it’s the combo of crap that we cobbled together over the years, but when all the shocks are in good condition, it does give a nice firm ride.
I’m getting ready to do it over again, so I’ll probly go with whatever NAPA sells, as our dealership owns the local CRAPPA store, therefore making repair parts super cheap and most of it has a lifetime warranty.
But I will uses a set of frt springs out of a 97 mustang GT to see how they feel/operate…..they are almost new.
I think the most noticeable and effective upgrade I did in the beginning with the Fairmont was the addition mustang upper and lower control arms and rear sway bar. That got rid of a lot of the body roll that Fairmont’s are famous for. My rear control arm bushings were pretty worn-out, and as I had parts lying around…..i am not changing bushings. It was later that I changed the rear springs.
Having said so, I seem to remember the rear lower control arm bushings on the Fairmont were round, and the ones off the mustang were oblong. No difference noted in lenghts.
One would assume the fox body mustang lower kit would work fine on your Fairmont, I seem to remember that they offered the same spring kit for a Fairmont. Call them, they will always assist.
good luck.