The change was due to 5-mph energy-absorbing bumper regulations, which were phased in over two years. In 1972, only the front bumper needed to comply. Most 1972 cars had energy-absorbing front bumpers and rigidly-mounted rear bumpers (hence the metal filler). For 1973, the rear bumper needed to be energy-absorbing, too (hence the flexible plastic filler). Chris in LA KerryPinkerton (pinkertonk@xxxxxxxxx) wrote: > They both have fillers, the 72 was gray metal and the > 73 was gray plastic. Looks the same until you touch > them. Same size. Don't know why they made the > change. My parts car is a 72 and the bumper guards > and these fillers are the only differences I noticed. > I'm sure there are some other small details such as > the DAM- Ticking Chronometer in the 73...