I got this list of applications for these brackets from the Kore3 site:
1964-1979 Buick Gran Sport, Skylark, Sommerset Regal, Special
1973-1977 Buick GNX, Grand National, Regal
1962-1979 Chevrolet Chevy II, Nova
1964-1977 Chevrolet Chevelle, El Camino, Laguna, Malibu
1967-1981 Chevrolet Camaro
1968-1977 Chevrolet Monte Carlo
1991-2002 GM S-Series Truck/SUV
1964-1977 Pontiac GTO, Lemans
1967-1981 Pontiac Firebird, Trans Am
1973-1977 Pontiac Grand Prix
1967-1977 Oldsmobile 442, Cutlass