I never liked those grilles much either. I don't recall ever seeing one with a custom grille. Some people mold them in and paint them but it doesn't really help much.
I didn't like the grille in my 47 Ford pickup so I replaced it with a 58 Studebaker Hawk grille. I cut a piece of steel to cover the opening and cut a hole for the grille in the middle of it before I welded it on. I don't know how it would work on the Chevy. The Ford was flatter across the front. An old Valiant grille has the same shape but is a little bigger. A 60 Chrysler is even bigger than that. With the Chrysler Grille it's almost required that you have slanted quad headlights.

Here's the 47 with the Hawk grille and split bumper. I also opened up the vents in the sides of the hood and extended the 3/4 inch bead straight back and down in front.