It looks like the Billet grill mounts in front of your existing grill
There are drilled holes on the 2 end uprights and I tried it,
it fits in front of the grill and is a perfect fit inside the grill frame surrounds or you would make up brackets.
If you wanted to fit the Pony you would have to use washers behind.
Most people do not put a pony on the Billet grill