That pic above isn't my own car, it's just pulled off the net.
Here's a shot from a pushbar replica seller. It shows the shape of the side plating.
Notice that the front section of the side plates (where the round tubes mount) is
NOT exactly perpendicular to the long straight section that passes under the Charger valance panel.

When it comes to GL replicas the pushbars are normally bolted on. Usually, a bolt through the side plates & going through a factory hole in the subframes. It's not as solid as welding it but the bar is attached tolerably well this way:

The common attachment method for the chrome bumper is using the license plate bracket holes. Check the little flat plate welded onto the back of this pushbar's lower round tube. (Smith Bros picture) If you choose to go this route then it wouldn't hurt to drill the bumper's holes out a size bigger for thicker bolts. Or at least use grade-8 bolts on the small holes.
As for the mounting height, there was variation on the TV cars. Sometimes the lower round tube was pretty much even with the chrome bumper's center protruding fold, other times the round tube was a bit lower. The spacing between the round tubes varied a bit too.