No instructions with the kit. I am guessing all trucks have the brace that runs from the front of the cab to the rear of the cab (just under but not attached to the roof sheet metal). The front of this brace is connected to the inside lip of the roof sheet metal just above the mirror. Same place the rear view mirror connects but higher. The rear of this brace connectes to the rim of a stock small window 56. I am not sure where it connects on a big back window, but it looks like it will only connect in one place and that would be the seam where the cab sheet metal meets the back wall sheet metal.

56 was the only year the big window was offered as an option. Im betting the big window option comes with the brace installed. If a dome light was included with an option, it was installed. If not, Im thinking the brace would still be there under the headliner.

 

I think I have a lead on a guy who has two original big back window 56 cabs stored on his property. If they are original, I will get more information and post it here. Someone correct me if I am wrong, I do not believe there is any symbol in the identification of 56 Ford F series truck that determine if it is a big or small back window.

 

Why not contact Bigwin56f100, he has to bare bones 56 big windows he is selling, he should be able to provide a picture of what was there.

 

I would certainly welcome and encourage his input. Meanwhile, I did go visit the owner of two 56 Big Window Cabs. The patch from Mid Fifty is a dead ringer, including the inside sheet metal flange that is on the original. The roof bracket that runs from the front of the cab to the rear of the cab is identical in both trucks, with one excpetion. The bracket in the big windows is shorter which raises the location of the dome light location in a small window to a higher location to clear the window in a big cab.

I had removed my dome light bracket that mounts the dome light above the window on one end and the front cab (close to where the review mirror mounts). It was also identical to a 55.

I feel 99% sure both dome light brackets are identical with exception one is shorter than the other to accomodate the larger window.

I also looked for a physical difference between the stock big back window and the conversion piece made by Mid Fifty. I could find nothing that would indicate a conversion. Obviously the weld across the bottom and rosette welds opposed to factory spot welds under the upper window sheet metal would be a good indicator, but these trucks get a lot of body work so either weld could be smoothed over and leave no trace of a conversion.

If the stock brace in a small window will be removed in the process. If its moved correctly (drilling the spot welds), and the holes are welded shut, I do not think I could tell its a conversion.

While this brace is standard in the small window cabs, its not used in the big window conversion or the stock big window trucks. The replacement patch panel has the inside sheet metal shell included which is exactly what the original big back window has.

One other question I came across is the trim piece in the original big back window. I have heard it only came with the trim ring. I have also heard it came without the trim trim ring. The 56 Im building with the big window conversion is going to be "blacked out", so I do not want the trim ring. I also dont care if anyone knows I have the conversion big back window. I have included that in the build pics that go with the trucks rebuild alblum.

I have photos of how the stock roof cab brace mounts to the stock big back window cab if anyone is interested.

 

He said early on he has the truck stored and can't get to it. Meanwhile, I found two I could compare side by side along with several other small windows this guy had in his yard. In addition, I had the original roof/dome light bracket out of my truck to compare. Comparing all this together at one time, I feel confident I have it correct.

 

I have bare cabs here that are BBW factory 2 of them. I will try to get you pics if you still need them

 

I posted that back in 2012!

 

lol, my oversight. Well I have pictures for myself but they were taken on my cell phone. I sent them to my email on my computer but I cant figure out how to send them to this site from email on my computer. That said, I think there is enough interest for you to post what you have here. I will compare what you have with the two big window cabs I took pictures of this afternoon and we will have four to compare. That would pretty much validate where the dome light is mounted in addition to confirming the big windows did in fact have the dome light hardware to mount a dome light if having or not having the light was an option. Thanks pointing that out Kevin, I totally missed the date on that post.

 

Here is a picture of the dome light in my original big back window 56 Custom Cab.

 

Thanks JC. Thats an exact match to the two stock 56 big window cabs I took photos of yesterday. Right behind that rubber seal, the bracket for the dome light is tack welded to the back side of the window frame. The window and the bracket overlap each other.

 

That's exactly what all my big window cabs look like

 

Thanks to you lucky big window guys who offered information on this subject. With the two I looked at yesterday, that confirms four original big back windows had the dome light and where it is mounted. If anyone would like a photo of what the bracket looks like behind the rubber, I can provide that by text or email. Just pm me with a number or email address.

 

My big window conversion has gone really well to date. I did final fitment on the bottom butt weld by using a rotary air grinder to get within 1/16" of the scribed line, then used a coarse ******* file to file to the finish. About 85% perfect fitment. Only one place where the gap is big enough to take a piece of 16 guage steel. Probably 6-8 inches long. the rest is almost a perfect fit. On these big window conversions, its a little out of my league to make the spot welds in the top section where the patch connects to the stock cab roof. Its too tight in there for me to get a spot weld (rosette) with a mig. Im thinking I have two options. First, use panel adhesive on the top seam. Second, weld the seam shut from the outside so the back of the cab and the roof all look to be one piece, not two as in stock. The sides will be rosette welded, and the bottom will be butt welded.

I am wondering if the reason you see a lot of big window conversions with no seam above the rear window is becasue its difficult to spot weld. I have no idea how they got a spot welder in that area when these were put together.

 

I believe, at least based on local trucks, that anyone who goes through the process of conversion to a BBW would want to go the extra step to add the custom filled seam. Another option is to buy a spot welder like this one: 120 Volt Spot Welder using a coupon the price maybe within reason...all depends on how "stock" you want the job to look. If you want the casual observer to believe that your BBW came that way from the factory you may want to leave the seam intact.

 

I have reservations about filling in the seam. If I weld it in to close the gap (stock seam), Im afraid I will risk the chance of a ghost line. The metal would obviously be quite a bit thicker in the seam and shrink and contract at a different rate than the sheet metal on both sides of the seam. If I understand correctly, this is what creates the "ghost lines" when thicker metal is added to stock sheet metal. As in backing plates or lap welds used to weld in sheet metal patches. I will check out the spot welder you posted, thanks charlie.