It would not hirt to do what you say and put the bushings on cup facing the rubber on the 73 up. It will help the bushing life . It will also make the front end alot less flrxable and help handling. This was only done to alow more movement and a softer ride. The performance 73 up suspension they faced the rubber to give the car a firm suspension . Here is a pic of a 73 340 front suspension that was never taken apart since new. Notice the cup faces the rubber. newer kits tell you to face them away . the bushings are alot larger then originals and it helps promote sales when they fail.