As I remember it was kinda a problem to install one because they were made universal fit.
We always stuck them out from the corner of the dash under the windshield.
Then we gave up on that and started mounting them on center of the roof. It was an easy mount plus it gave you a spot lamp in all directions.
I know that's not what your looking for, so If it was me I'd stick that thing out thru a new hole where it looks good and weld up the hole in the A pillar.
Dan
