Non-Chevelle, but may apply: bought an 88 firebird for my daughter, seller said rattle in front end of car probablly a strut or balljoint. Well, everything seemed fine. After much searching, discovered the drivers' side disk caliper was "Rattling" on the pins that hold it in (they were tight). Turns out the caliper has 2 rubber bushings that fit into the caliper body where the pins & metal bushings go thru. NAPA had a replacement kit with the new rubber seals and the metal bushings that ride on the pins. Quieted it right up!