Marchal fog lights on an 87-88?

Found a complete 85TC in the local JY recently.   In addition to scoring random odds and ends, and the full Garret T3, I was surprised to find this car still had the cool Marchal fog lights with the cat in the lens!  So of course I grabbed those too.

Now it's obvious the Marchals are a little bigger than the generic foglights in the '87-88 cars.    However, a quick mock up suggests they might actually fit into the valence opening, and even fill it flush or seamless-surround, as if the opening was made for that size lens in the first place.   You wouldn't be able to put the covers on of course but that's fairly rarely seen (and I only found one cover in the car anyway). 

I haven't yet physically or mechanically tried the swap yet so while I was on here I thought I'd ask if anyone has tried this conversion already?   What kind of aggravating bracketry or wiring conversion might be needed?

Update since I finally had a little time to mess around with this idea tonight.  It seems the Marchals can be made to fit but some work will be required.  The Marchals are almost identical in width as the OEM Hellas on 87-88 cars, yet display significantly more glass thanks to a thinner bezel.  The problem is they are also about 3/4" taller and their mounting bolts are at the bottom of the housing, unlike the Hellas which have their bolts in the middle.   Happily though, they plug right into the same connectors, so no wire muckery is needed.  Yay!

An 87-88 fog light bracket has a hole for a middle mount, not a bottom one, so you can't drop a Marchal into one.  However, the brackets are easy to remove and by doing so I was able to mock the Marchals within the bumper.  As I suspected they fit (if only just barely), at about the same recessed depth, but the lower 1/8 or so is covered by the bumper - same as the Hella fitment, oddly enough!  Still, they look better to my eyes thanks to the larger glass area, "pinched" benzel, and the black cat which is a fun bonus with racing heritage (and a nod to our sibling Mercury Cougars, heh).

You can possibly use the factory brackets by drilling an additional hole to suit the mounting bolt on a Marchal.  But I also suspect you'd have to bend the bracket's lower horizontal plate downward to provide sufficient clearance to insert Marchals from the front, through the bumper cover... as it is, there's just not enough clearance to rock a Marchal into place because it hits the top of the inner bumper core and there's no way you're gonna bend that. 

To be frank, I'm not sure that lower/horizontal part of the bracket is strictly needed:  both light styles (Marchal and Hella) mount directly to the vertical portion, with a single bolt.  And they don't even touch that horizontal part!  I suppose it's there to provide support if the bolt ever loosens, to keep the lights level and/or prevent them from falling out.

Anyway before going further I'll probably go back to the JY and pull the brackets off that donor '85.  I honestly don't know or remember what they look like, so I'm not sure if they will swap over (doubtful) but IF they do it could be less aggravation for sure.  Worst case, they're better "spares" toward modifying to fit.

And of course all of this is not-so-conveniently distracting me from the need of a new clutch master cylinder, d'oh...

I managed to finish the conversion and I think it turned out well!  To no surprise, it's not as simple as a drop-in swap, but it's not terribly difficult either.  Parts in hand, you can probably mod and install in 90-120 minutes.  You'll need a 10mm socket (and ratchet), 13mm socket, drill press, and a Dremel with a router bit.  Oh, and a set of Marchal 750's (with mounting spacer and nut) as used on upmarket 80's FoMoCoupes. 

To get started, unplug each of the OEM foglights and use the 10mm socket to remove the bracket bolts.  There are 3 per light and they're easy to reach from beneath the bumper.  Once loose, finagle the bracket out through one of the lower bumper valence opening/slots toward the center of the car (the center ones are larger).    A Caveat: you might need to remove the lamps first, using the 13mm socket.  Mine were already out from earlier experimenting and so I'm not sure if whole assembly will fit through the opening.  Probably not.

To adapt the bracket to support a Marchal, you'll drill a new 9/16 hole about 1.5" below the OEM Hella mount hole.  I did write down the exact measurement I came up with but lost it, bah, and now the lights are mounted so... see the photo below, you'll get the idea.

Unfortunately, that's the easy part.   The hard part concerns the OEM opening in the front bumper core: since the 87-88 cars have an angled front, the fog light recess is not uniformly tall enough for a taller Marchal to fit plumb.   You'll need to hog out and remove some of the bumper core fiberglass in the upper inboard corners, to clear the Marchal housings, so that they point straight ahead as they should.   (Verbosely, looking at the front of the car, for the left light you'll remove material from the top right of its opening; for the right light you'll remove material from the upper left).   You do NOT need to touch the bumper cover, only the hidden solid fiberglass core beneath it! This mod is virtually undectable - once installed, the lights will hide all trace of work.   Use the lights to test fit as you go.   You'll remove about about 1/4" thickness of material across an area about 2" wide and 1" deep.

Once satisfied with the fitment, slip the brackets back into the bumper area but don't mount them.   Place the OEM Marchal spacer on the back of the light and slip this assembly through the front opening.   The spacer is important!   Without it, the lights will be angled downward, and not flush in the opening.   Now the tricky part:  You'll have to feed the light's threaded mount stud into the new hole you drilled on the bracket, while both items are loose.   It's tricky but doable.   Once accomplished, put the 13mm nut on the stud to keep the light from falling out, then mount the bracket to the bumper core.  Then make final adjustments to the light and tighten the nut.    Plug the lights back in (there's juuuust enough slack) and done! 

It's not the most dramatic upgrade, but it's subtle and classy and IMO a better nod to racing heritage than the plain ol' boring Hellas.    Plus IMO they look cooler as they DO fill the space better.   Your opinions may vary.