It's strange that one side is ok and the other isn't. I assume both tires are the same size. If it hits the bottom of the spring cup it seems like one strut is shorter than the other. This could indeed be the case, as the escort had longer struts to fit bigger diameter wheels. It could be that one side is Sierra Cosworth 4x4 and the other is escort cosworth.

What struts do you have and are they the same part number?