Lil Red;
Lotsa people giving their "learned opinions" without giving you the true answer you need. Forget about Oven Cleaner. The only way to remove anodizing correctly is with EastWood's Anodizing Remover.
Do not let it rest on your fingers, wash it off or use Gloves. It is some bad stuf, but works amazingly. I have been polishing and restoring 67-8 Cuda Grilles for years. Nothing else comes close to this stuf. Very inexpensive and it lasts forever.
Your truck grille has very thick anodizing, so it may take 2 coats.
Good luck, Brutha!