As I recall:
On the rears, the pigtails both point-to the drivers side. This is important.
Going to resurrect this old thread for some clarification. Do the pigtails at the TOPS or the BOTTOMS of the rear springs need to point toward the driver's side? More specifically, do you mean that that the very tips of the springs point "left" (like if you were using your index finger to point toward the left of the car from the spring location)? The Bullitt suspension has been on my car for nearly 4 years, and the right rear is sitting 1/4"-1/2" lower than the left. We had re-used the stock isolators, and they seem to still be ok (considering they are nearly 10yrs. old). Thanks!
Modern springs really don't sag per se. The isolators being shot is a real likely deal. Or the unibody being slightly tweaked is possible. When I put the Mach 1's on the fox, the original isolators came out. Wow, they looked like baked dung.
You might just need to shim the spring on the low side. You can use a knuckle inside the coils (kinda ghetto) or use a perch spacer (Global West and Steeda sell them IIRC).
One thing to consider: It's been widely accepted that the cars are pitched diagonally. For instance, if your RR is low, is the LF a little higher than the RF? This was NOT the case on my fox, but it seems to be an accepted philosophy on Fox chassis cars (which ours are. Fox IV). On the fox, I was able to raise the LR (my low one) up, and it actually brought the RR down a little, so as to even it out a hair. Not that this applies to you - just my experience tinkering around with this crap. My 94 (Prokit) sits right-on all the way around.
Good luck.
Which got me to think about where one measures from and the assumption being made. If one is measuring from the ground to the bottom of the fender is it reasonable to assume that the measurements should be the same from either side to side of from front to back. I can forsee that these reference points might not be the same due to assembly differences. So where are the correct reference points? Has anyone tried a laser leveler both side to side and front to back to confirm the reference points? Maybe at the end of the day it's just a visual thing. If it looks right that's all that matters.
We think alike. I normally only worry about unevenness because of the aesthetic. So [personally] I measure height from the ground to the top of the fender arch. I do all my tweaking to alter that (and only that really).