I've studied your pictures and still am not clear on what your rear suspension is set up at. It looks to me like your frame is very close to the top of the axle housing. When I first saw your pictures after you had it painted I felt the rear was a little low making the tires too close to the fenders. I edited the one picture to turn it right side up, and it appears your shocks are set up that way to get the car as low as it is.

I would disconnect the shocks and raise the car up a couple of inches in the back and then take a measurement from the bottom perch to the top perch and order a set of 140 lb coilovers that rest at that dimension. I think it is a distinct possiblility your frame is contacting the housing, or at least being prevented from doing so by the shocks bottoming out.

Don