https://www.mamotorworks.com/corvette/product/corvette-1974-1978-seat-back-hinge-pivot-bolt-bushing-kit-4-pieces-602241
1974-1978 Corvette C3 Seat Back Hinge Pivot Bolt Bushing Kit 4 Pieces 339166 - 339166
4-piece kit restores smooth seat back pivot action by replacing worn hinge bushings/bolts, reducing play and binding for proper seat movement.