[jonzcustomshop]

the grille support panel will work, you will have to fill the chevy grille mount holes, and put your own gmc holes. the upper outside holes will be the same.
the inside dual headlight is a little close (the plug) on a gmc grille on a chevy support, however I put a gmc grille on my chevy, and it works fine.
the support itself will bolt on with no mods needed.

60-62 had a different support (no frame notches) , so make sure you get a 63-66.