OldSub is right, the cross member/radiator support is crucial to a strong front-end. If you are gong planning on using the original GMC sheet-metal, the Chevrolet cross-member is located in the right place for the radiator support. I can't remember if I had to re-drill this piece to mount my radiator support after I changed out the GMC support for a Chevy. I do remember that everything fit afterwards.
