i just put on the rear shocks and springs and sway bar yesterday, no time for front yet. i got KYB AGX's with H&R OE springs and ITR sway. question is, right now the rear left is sitting little bit lower than right. i'm not gonna really check it till i get front done, cause front left shock is sitting lower than front right already i'm guessing cause they shocks and springs up there are old. if i put on the front shocks and springs and there is still difference in back, what do you think problem is?

 

You should probably wait a couple weeks for the springs to settle after getting them all installed. If the rear left still sits a hair lower, you can easily swap the rear shocks/spring assembly left to right and let your weight (driver sitting on the left) to help even it out.

 

i'm thinking i should check the very top self locking nut on the shock on both sides to see if they are the same. i put them together at different times and never checked them together

 

Well you should always torque the top shock rod nut after installing the assembly in the car, but it will not affect the ride height since the weight of the car rides on the springs. If you just threaded the top nut on enough to hold it together, then installed the assembly in the car, when you went to tighten the top nut it would just pull the shock rod up out of the shock housing slightly.