Are you trying to keep thieves from getting in the bed, or from stealing the tailgate?

A while back I was at the local u-pull with a friend, he wanted a tailgate for a '94 up, and one of the ones he was eyeballing had a "band" clamp around the right side pivot point, it sure looked factory, painted to match the truck and truck was not repainted ... kept the gate from being easily removed.

We moved on to another truck, better gate. None of the other similar ones had the clamp.

It was a Texas truck, I suppose it could have been a mexican market import.

Any way, it was effective enough, we moved on too.

For that purpose I think a mere hose clamp perhaps with a torx head or something would be enough.

Eliminate the quick grab and most will move on to another easier one ...