67 cuda grill

One more thing... Two different ways to go about this. I can't say which is easiest.
At my third rodeo I had a helper. We pulled the front bumper and the header panel. Bolted the grilles into header panel off the car. Easy access to all those fasteners. Downside is the bolt ears on ends of header panel can scar the paint on the fenders. And when I closed the hood I found I needed to loosen a few bolts again to adjust that body line. Just hand and eye matching the little radius at fender to header panel didn't work.
Adding bumperettes at bumper brace bolts, adding a lamp to front tag mount, some spray bomb painting here and there were my reasons for going this route. good luck with yours.