1966 - 1967 Corvette U Nut Grille Upper Correct Reproduction 1 Piece 1966 1967 Corvette grille u-nuts special correct, GM part number 3831934. Part number 3831934 nuts were used in 1 place on the 1966 and 1967 corvette at the center of the grille. Nothing like the original was available until now. These exact reproduction u-nuts are visible when installed on the car! These are new reproductions of the original part. There has been no correct reproduction of these nuts, just a generic version u-nut that has a hex steel nut instead of the square nut like the original. Judges look for these! Get those extra points! Note the "m" logo on each nut. Fits: 1966, 1967 corvettes.