Have not heard too much about OER grilles over the years, but based on lots of other OER parts, fit is generally poor to horrible.
On the other hand, most repop front bumpers are also a poor fit. You don't say if your bumper is original, repop, rechrome, etc. If original, the the original grilles fit well, then you can rule out the bumper. bumpers that have been rechomed, 'may' have been straightened before chroming. It is possible the straightening process actually bent the bumper out of shape.
If you can find or borrow a set of original grilles, you could narrow down the problem fairly quickly.
I used to be indecisive. Now I'm not sure. I feel like I am diagonally parked in a parallel universe. 1968 400 convertible (Scarlet) 1976 T/A - 455 LE (No Burt) 1976 T/A New baby, starting full restoration. 1968 350 - 4 speed 'vert - 400 clone (the Beast!) 1968 350 convertible - Wife's car now- 400 clone (Aleutian Blue) (Blue Angel) 2008 Durango - DD 2008 GXP - New one from NH is AWESOME! 2017 Durango Citadel - Modern is nice! HEMI is amazing! 1998 Silverado Z71 - Father-daughter project 1968 400 coupe - R/A clone (Blue Pearl) (sold) 1967 326 convertible - Sold 1980 T/A SE Bandit - Sold
