Mod Box - 85' Grand Marquis

[Mr Bean]

I spent a couple of hours after work tonight lowering donor body onto the ground then took some measurements of the 2 cars to compare how much work will have to be done. At this point it looks like the 85' body will simply bolt onto the 07' frame with no modifications. My main concern was the 4 body mounts at the front of the firewall but they measure out to be in the same locations. Actually I discovered that Ford did so little work to these cars over the years. For example the 07' has holes in the firewall that are used on the 85' for bolts.

Box bodies have longer windshields which stretch down further onto the firewall. I was hoping the wiper cowl would simply bolt on but I will have to do some mods to get it to work.

[pantera77]

At this point it looks like the 85' body will simply bolt onto the 07' frame with no modifications. My main concern was the 4 body mounts at the front of the firewall but they measure out to be in the same locations. Actually I discovered that Ford did so little work to these cars over the years. For example the 07' has holes in the firewall that are used on the 85' for bolts.

That's sad yet great news at the same time.

[Piece-it pete]

It's simply amazing. They did do mods where it counted though.

Nice work Mr Bean! It's fun to watch.

Pete

[sly]

it would be epic to do a complete roller swap of an 05+ on my beater and make it an autocross car. I would have to come into some major funds first because I'd also do engine/trans/rear axle/springs/shocks/wheels/tires/willwood (or similar) brakes.

stuff like this gives me happy thoughts.

[87gtVIC]

Box bodies have longer windshields which stretch down further onto the firewall. I was hoping the wiper cowl would simply bolt on but I will have to do some mods to get it to work.

I am not following this. What does swapping a frame have to do with a wiper cowl?

[Mr Bean]

I am not following this. What does swapping a frame have to do with a wiper cowl?

I am planning on swapping as much modern electronics as I can while still leaving the boxy body. The wiper cowl was one of those and since I had it off I test fitted it. Just threw it in there, has nothing to do with frame swap.

[87gtVIC]

I see. I missed that in your posts.

[Mr Bean]

I ran into my first issue tonight. I was unbolting the 85' body off the frame and one of the body bolts decided it didn't want to come out and eventually just decided to spin inside the body. I am guessing the nut that was welded to the body broke off. It is the second body mount from the rear of the car. I thought maybe the bolt came out inside the trunk but no such luck, it's below the floor board. Surprisingly there is a spot of rust on the trunk floor right next to where that mount would be. What's the best way to deal with this? Should I just cut an access hole in the trunk so I can vice grip it and then weld a patch in there after it's done?

[marquisman]

Since you will have to replace the nut that is in the boxed area yea, cutting a clean access hole is best. There are other ways but, now is not the time to be a sloppy mechanic.

[chitownvic]

Such an awesome project and I vote for cutting an access hole


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[87gtVIC]

Cut the hole. I had to do that in a few places for my car. Add a patch afterwards. My car was rusted out on both side by those mounts.....though those bolts buzzed right out lol.

[pantera77]

What's the best way to deal with this? Should I just cut an access hole in the trunk so I can vice grip it and then weld a patch in there after it's done?

Yep, cut a hole then weld it back up. Had to do the same thing on my 89 in a few spots.

[Mr Bean]

Making slow progress tonight. Cut a hole in the trunk and snapped the last body mount bolt.


Here is the bad spot. Turns out there is a channel underneath the trunk floor where water and dust can collect. There is actually a drain hole in the corner but mine was all clogged up with crap. No wonder it rusted.



I also did some more checking and measuring. Rear of the frame is exactly the same on box and whale. There are unused holes in the 07' frame that are being used on the 85'. Box rear bumper bolts right up to the 07' frame. They added an extra support to the 07' frame between the frame rails which is kinda nice actually. Makes it sturdier.

If everything goes according to plan I am hoping to test fit the 07' frame tomorrow.

[HiFiMerc]

I think that support has been there since '92.

I'll have to check to make sure those channels are clear when I get the box out. If it ever warms up....

[pantera77]

I think that support has been there since '92.

PI boxes had that support too. If your talking about the rear most one.