If you want to change your somewhat unique special hansome GMC into a common everyday run of the mill Chevy we need to know what year Chevy grille you want.

69-72 Chevy fenders are different from GMCs.67/68 are the same.The core supports,center bar,wiring,& hood latches are different.If you are going from`69 GMC to 67/68 Chevy you need a 67/68 hood.67/68s have a gravel shield below the grille.If you are going to 67/68 you can use your core support and modify the headlight buckets.