You may know this, so forgive me. The big bumpers mount in the engine compartment with a giant carriage bolt through the frame rail. I assumed the new brackets would do that as well but I was mistaken.
Steve told me to take the grills off and I would see a bracket (for what I don’t know) that the later cars had on each side and to replace that piece with the small slider type bracket he sent in the kit.
It took some adjusting but they are in there.
I will say I would have like to have used the original beefier bolt in the frame rail. The new hard ware is a little smaller but we all know these bumpers do nothing anyways!!