Bill....For this low movement area of the car, you can get away with almost anything for a while...... but like you already knew,the aluminum cap against the aluminum bushing will slowly fight each other and wear, in time causing slop that you can't tighten away.........IMO the longest lasting and most frictionless combo is the aluminum cap and the stock black bushings.......all of the delrin bushings iv'e used in this area gave some unwanted slop after a couple runs........ Don't make too much work for yourself on shock caps
