Grille headaches

[chevyhed53]

Decided to replace the old, rusted body-color grille on my '56 with a chrome unit. Set the new chrome unit in place and wasn't happy with the gap on one side. Lower valance had about had it, too, so I bought a new one. Took everything apart again, and had to trim the valance a bit to get it to fit, but when I was done the bolt holes lined up nicely and the gaps between valance and fenders were nice. Only one problem--now the new chrome grill doesn't fit. The flanges at the top and sides get hung up and it just will not budge into place.
I figure that maybe if I loosen up the side bolts on the valance the fenders will move outward just enough to slide the new grille in, but I'm not optimistic. Any suggestions? Any tricks to setting the grille in right? The valance is from Eckler's and the grille from Brothers, but I think they're probably all from the same manufacturer. Appreciate any tips.
Thanks.
sr