Box Body Roof Modification Questions

[TomO]

Hello -- some box bodies were built with a sort of extended roof that was a plastic cowl type roof extension that was put over the rear window that extended the roof rearward and apparently was for the purpose of making more head room in the rear seat.

Does anyone have any knowledge of what is involved with converting this type of roof back to the standard roof? In other words, removing the plastic roof extension and reinstalling a standard rear window.

I'm guessing it would be fairly straight foward -- i.e., removing the vinyl top, removing the roof extension, clean things up and have a shop put in a new rear window gasket and window, find some std. rear window trim and install the trim.

However, if somebody has done this before, I would greatly appreciate any pointers/advice etc., or perhaps there is some reason that this type of modification would be ill-advised.

Any input would be appreciated. Thank you.

[Ziggy]

Any pics of this which you speak? Don't think I'm aware of any extended roof box sedans... I'd like to see one.

[TomO]

Any pics of this which you speak? Don't think I'm aware of any extended roof box sedans... I'd like to see one.

I don't have any personal pics, but if you look through the reader's rides section, there are plenty. Here's a link to MercuryGM88's post that show's the roof I'm talking about.

http://www.grandmarq.net/vb/showthread.php?44615-My-88-Grand-Marquis

They can be identified by the fatter C-pillar at the top, plus the smaller back window, and they usually have a thicker-looking more heavily padded vinyl roof.

[mercurygm88]

Ahh yes that would be the formal coach roof option. Which I personally like more than the regular ones not really sure that it actually gives anymore headroom than the regular roof though.

[86VickyLX]

No... There is no extended roof box.

[TomO]

No... There is no extended roof box.

Mercury88GM knows what I'm talking about. Yes, "coach roof" is the term I was trying to think of. Thanks Mercury88GM. Hope you don't mind me using your car as an example. It's a beautiful car.

I was wanting to make one into a standard slicktop -- so that's the reason for my inquiry.

--EDIT-- Actually, Chrysler had a very similar option that they offered on their 80's New Yorkers and possibly the Gran Fury and Diplomat (which were the same car).

It extends the rear upper part of the roof rearward and moves the back window to a more vertical orientation. It's accomplished by "grafting" some sort of plastic or fiberglass piece onto the back part of a standard roof.

[mercurygm88]

Mercury88GM knows what I'm talking about. Yes, "coach roof" is the term I was trying to think of. Thanks Mercury88GM. Hope you don't mind me using your car as an example. It's a beautiful car.

I was wanting to make one into a standard slicktop -- so that's the reason for my inquiry.

--EDIT-- Actually, Chrysler had a very similar option that they offered on their 80's New Yorkers and possibly the Gran Fury and Diplomat (which were the same car).

It extends the rear upper part of the roof rearward and moves the back window to a more vertical orientation. It's accomplished by "grafting" some sort of plastic or fiberglass piece onto the back part of a standard roof.

Yeah I know what your talking about with the chryslers but as far as what ive been told our boxes are differnet. I have been told that the only difference between the boxes with the regular rear window and the coach roof is that part of the window is coverered on the coach roof cars and that it is still the same underneath though I have no proof of this. Being that your car was a formal coach roof car and you removed the vinyl what did you find underneath?

[mercurygm88]

No... There is no extended roof box.

It may not be extended and I dont think it is but it is quite a bit different than the others.

[86VickyLX]

The Crown Vics/Grand marqs with the coach roof simply had a fiberglass shell installed INSIDE where the standard rear windshield would be. Other than that the roof is the same. Town Cars are very different.

[87gtVIC]

There were some pictures of the shell posted many many years back.

[86VickyLX]

There were some pictures of the shell posted many many years back.

I remember seeing these pictures. Don't remember where...

[87gtVIC]

I think Tom took the original pictures...in a junkyard down south somewhere.

[88Vic]

What's different about the Town Cars? Mine has the coach roof and I eventually want to convert to slicktop as well. I hate to copy but I want mine exactly like Zoomie's Town Car, slicktop and the body painted flat black (and have my windows re-tinted to 35% all around). Is the coach window itself smaller than the rear window in a non coach roof car? If so i'll just buy a whole new rear window and put it in, and work on prepping the body for paint in the meantime.

[TomO]

Yeah I know what your talking about with the chryslers but as far as what ive been told our boxes are differnet. I have been told that the only difference between the boxes with the regular rear window and the coach roof is that part of the window is coverered on the coach roof cars and that it is still the same underneath though I have no proof of this. Being that your car was a formal coach roof car and you removed the vinyl what did you find underneath?

I don't actually have possession of the car yet, so I don't know. But from all of the photos of boxes with coach roofs, it sure looks like the angle of the rear window is steeper than a standard roof. Also, the C-pillar on the coach roof boxes looks wider at the top than the standard roof C-pillar. That's why I was assuming that the roof was extended rearward a few inches on the coach roof boxes.

In fact, when I look at the photos of your car taken from the side, where the C-pillar is visible, and I compare them to a non-coach roof car, the shape of the C-pillar looks drastically different to me. That is, the C-pillar on coach-roof cars looks like it's nearly constant width all the way up, whereas, on non coach roof cars, the C-pillar tapers markedly from bottom to the top.

I guess one way to know for sure is to measure the top of the C-pillar on a coach roof car and compare to a non coach roof car. But, since I don't have access to the coach roof car, I can't measure it.

However, I do have a non-coach roof car. When I measure from the top, rear corner of the rear door molding straight back to the corner of the roof, measures right at 10 inches.

[86VickyLX]

What's different about the Town Cars? Mine has the coach roof and I eventually want to convert to slicktop as well. I hate to copy but I want mine exactly like Zoomie's Town Car, slicktop and the body painted flat black (and have my windows re-tinted to 35% all around). Is the coach window itself smaller than the rear window in a non coach roof car? If so i'll just buy a whole new rear window and put it in, and work on prepping the body for paint in the meantime.

If you look closely at his pictures. You can see the retarded and weird body lines that the towncar has that hide under the vinyl and fiberglass top. For a good quality slicktop conversion on a TownCar, you better have a lot of money at your disposal, a good autobody shop, and a lot of patience... The smaller rear windows are the coach roof cars. Then there's the rag top versions. Which appear to be large rearview mirrors with a fiberglass shell over top of that with the cloth top wrapping that.