Lingenfelters brackets and carriage bolts can not be beat for the price and craftsmanship. Though they do not look stock, they seem to function like stock and once they are hidden behind the bumper, who cares.
Back in 1999 when I made the first STOCK appearing brackets and bolts for a 65' Coronet and a 72' Duster, no one but just a few wanted to pay for my time and materials, now they are made in sets such as these and it is a bargain. Go get 'em.

Now if you want to hide your cards in the crazy world of STOCK appearing, that's another story.