Someone on the forum said that a set of 88 T-Bird springs are taller or stiffer or something. I just bought a set from PartsAmerica.com. They're not taller, but they do seem like a higher spring rate. I might take them back if there is a better solution out there. Is there lift kit out there? or just some taller springs? This is for use on a 93 2.3L Hatch that I use for Rally.
Well, that might have been me, I did tell you that I put '84 Thunderbird REAR springs in my old '90 (along with 5.0 front springs) and they lifted the car around an inch or two. I don't know about the front springs, maybe they aren't taller. I don't know how high you're looking to go, but JCWhitney sells "ultra high lift" springs for '79-93 Mustangs, front & rear. Says they lift the car 2-3" or something like that, I doubt you would be able to make them work with stock suspension geometry but you could probably cut them a bit.
the TBird springs are indeed stiffer since they weighed considerably more than a like engined Mustang