I'll get to the removal and fix in a moment but first here are some notes the 71 grill inserts.
1. The grill insert is mounted to the grill shell by six Phillips screws - two on top, two on the bottom, and two hidden under the trim bar.
2. The trim bar is clipped to the grill insert in three places - left, right and center.
NOTE: The only downside to this fix is that the trim bar has to be installed after mounting the insert because the hidden left and right screws will be covered by the trim bar.
Trim Bar Removal
Starting on either the left or right side of the insert, removing the trim bar requires that you pull the trim bar downwards and outwards on the lower edge of the trim bar in the same motion to clear lower tab. If you do not, there is a risk of breaking the upper tab, lower tab, or both. It can take quite a bit of force.
The Problem
The PO of my 71 F250 had the truck painted a few years ago. The inserts have some light overspray but otherwise were very solid and more importantly, uncracked! Unfortunately, the right grill insert's trim bar had an unsightly gap.
Upon removal I discovered it was not securely clipped due to a broken/sheared upper tab. The other two upper tabs weren't much better.
A good lower tab
The Fix
It dawned on me that the trim bar is shaped like a "C", similar to the hood lip molding so I dug out the old clips from the parts bin. A trial fit revealed that the clips, when tightened, would rotate and tighten over the trim bar's "C" profile.
In the pic above, I pointed out the mounting hole used to secure the grill insert to the grill shell. But did you notice that there is also an unused hole? Yessirree! There is an "extra" hole next to each of the insert's three clips! Isn't that strange? Did Ford provide them just in case? Dunno... but we're happy that they are there!
Loosely install each hood lip molding clip in the "extra" and unused holes, install the bar, and tighten the molding clip's 3/8th-inch nut. Double check that the clip did indeed rotate and hold the bar. Snug 'em up.
The Finish
No gap and the trim bar is securely fastened.
NOTE: Dennis Carpenter sells replacement hood lip molding clips which are slightly larger, have plastic bodies, and don't have that wire tang. They would work even better than these OEM clips.
