For owners of 1953-’56 Ford F-100 trucks, upgrading from a small back window to a big back window has become a highly sought-after modification that blends style with practicality. The original small rear window, while true to many factory builds, can feel restrictive by today’s standards. In contrast, the big back window option offers a noticeably improved look, giving the cab a more open and proportionate design that stands out at shows and on the road. This change not only elevates the truck’s classic appeal but also enhances the overall driving experience.
One of the biggest advantages of the larger rear window is the increase in natural light inside the cab, making the interior feel less confined and more inviting. Additionally, the expanded glass area significantly improves visibility, helping to reduce blind spots and making driving safer—especially in traffic. While factory big back window cabs are rare and often difficult to find, aftermarket solutions have simplified the process.
LMC Truck provides a big back window conversion panel designed to fit existing small window cabs, allowing enthusiasts to achieve this upgrade without sourcing a new cab. With basic tools and some dedication, the transformation can typically be completed over a single weekend.
Here’s the starting point with a small back window in a 1953-’55 cab.
Lay out all of your favorite tools that you may need. It is a good idea to add a variety for those tough-to-reach areas.
Open your new big back window conversion kit and set it on a work stand. We sourced ours from LMC Truck.
Mark the lower cut line. Our initial cut will be directly on the body line. Using ¾-inch tape helps make a nice straight line.
Mark the upper cut line. This line was made 1/8-inch directly below the roof seam.
There is a brace directly below the rear window that needs to be removed. Locate the spot welds on the left and right sides and drill them out with a 5/16-inch drill bit.
Using a cut-off wheel, cut through the entire upper and lower cut lines.
Using a belt sander, grind the spot welds in the left and right door jambs. Only remove the spot welds in between your upper and lower cut lines.
Remove the old panel.
Grind the spot welds holding the remaining upper flange to the roof skin. Use a panel separator to remove the flange.
Using a rapid strip disc, remove rust and paint from all mating surfaces.
One of the biggest advantages of the larger rear window is the increase in natural light inside the cab, making the interior feel less confined and more inviting.
Spray all mating surfaces with a quality weld-through primer.
Test fit the new back window panel.
Mark the bottom of the panel to make a final cut line.
Cut off the remaining section.
Drill 5/16-inch holes to plug weld the new panel in the door jambs and to the roof skin.
Mark the bottom of the panel to make a final cut line.
Plug weld the panel in the door jambs and to the roof skin.
Tack weld the entire lower seam. Hammer and dolly the seam as you weld to keep the gap tight and flush
Completely weld the lower seam. Spacing out tack welds and allowing proper time for welds to cool is key to not distorting the panel.
Grind all welds down as you go and finish with 80-grit on a DA sander.
Here is the finished product, we’re very happy with the results!