Those look like 71 Cuda only headlight bucket brackets, they will not fit on a 1971 challenger, not without a cutting torch and a welder . I think you will need to find a pair of 71 Challenger fenders, to convert to the 71 Challenger grille, because the front area of the fender is completely different between 1971 and 1972. I could be wrong, maybe another member who has done this swap will chime in on this.