Not sure which ES kit you have but the rr control arm kit I have used in the past is for each end of the trailing arm - part no. 6 in the diagram. 1 bushing goes in the knuckle and the other in the trailing arm.

I did this install and subsequently removed them due to the increased harshness.

If you post the ES p/n I can confirm.

Redcoat Raceworks. Performance parts and custom fabricating for Contours, Mystiques and Cougars. Specializing in chassis and suspension parts. Custom end links, control arms, strut tower bars, engine torque braces, etc.