PROBLEM FELLAS. With lowering springs, you really cannot bounce test the struts. It will always result in stiff. You strut is SHOT! My suggestions if you wanna keep the Eibachs in go CSK or swap springs to some Roadmagnets. I am the diehard asthetics guy, so please do not try and sell the seller on the car rides fine with Eibachs and KYB's, cause in reality, unless you have 0 potholes or dips in your city, the suspension sucks. I have lived this all too long.
Also, if you have aftermarket sway bars, the bushings may need regreasing. Hell, the rubber bushings need a touch of white lube. I have a lot of experience with this, so I AM QUALIFIED to make these judgements.