rear suspension links
 

is there a way to tell what orientation each link goes in? i did poly bushing upgrades but i didn't think to mark which link goes where and how it goes back. i know the difference between the upper and lower links but i didn't mark which one goes left or right. i might have installed them incorrectly. the reason i say this is one side of the car sits a bit higher than the other. i thought there was some binding so i loosened the bolts and put the weight back on the suspension then tightened them up. the car looks like it sags a bit on one side. currently, i have a set of adjustable spring perches to compensate for the sagging. i don't feel comfortable driving it like this... any advise on this would be greatly appreciated. thanks.

Lower links can be installed either way,front to back,side to side. They are dimensionally the same. The upper links are also the same in this regard. It must be something else causing this. Are you certain none of your links are bent?
You are supposed to have the cars weight on suspension before torquing any of that hardware.

Did the car have these symptoms prior to doing bushings? Are both rear springs seated properly? Maybe disconnect lower shock mounts and lower differential enough to remove springs and check their free length,it's possible one has sagged?
Original intent for adjustable spring perches is to adjust ride height-front to back,not side to side. If not actual problem with springs,you should investigate why the car doesn't sit level instead of trying to mask the problem with adjustable perches. Has this car been in an accident previously that you are aware of?

any picture on this would be greatly appreciated. Thanks!

Often 1st gens sit crooked with the driver side being a bit lower when looked at from the rear. Mine does this. My threory is that replacement of the stock exhaust, removal of rast nest and air pump and skewed the side to side weight a bit to cause the slight lowering on the driver side. The passenger side is now a bit lighter in this case. If its less than 1/2 in. I would worry about it much yet.

Poly bushings may make your car handle worse than OEM, I am not certain on this but there are many topics that cover it. People warn of snap oversteer due to binding.

One "upgrade" people do is make the OEM upper bushings softer and more compliant to help eliminate binding that can happen.

I am going with solid rod ends for lower links (Techno Toy Tuning) and OEM upper and Watts link replacements. Apparently the OEM rubber link bushings harden over time and can make things worse.

This is due more to sloppy jigs when cars were assembled/welded on assembly line. Some cars/customers had more problems than others,particularly heavyset drivers.
Dealt with a lot of these when cars were still under warranty. Some cars this was really noticeable with 1/2"-3/4" difference in ride height left to right. Mazda had at least one TSB to address this and supplied shims to place on top of driver side strut mount to lift car slightly. Shims were @ 6 mm and up to 3 could be stacked on top of mount,some cars i had to put 4 on to level them. Job paid .5 hr under warranty, Still have a dozen or so of these shims left over in one of my toolboxes.
I think Mazda has a part # for these still but i think they're 3 mm thick,not sure but think Mazdatrix lists them on their website so it's still possible to address the issue.

Good compromise to keep cars from being too tail happy is to use poly bushings in lower links and new oe Mazda upper links to minimize tightening of rear links. Works for some cars,not all and really altered ride height does not help the situation. Stiff springs seem to help this condition,at cost of ride quality.

I have poly-bushing everywhere, Tokico blue and RB springs, never been happier with the handling and the ride (tires are Toyo R1R, very sticky).
I have not experienced snap oversteer, when it slides, it is very predictive so far.

BUT I have the driver side about 3/4 of an inch lower at the rear... haven't looked into it yet, but will do this winter.