With all the aftermarket parts available these days, it's increasingly tempting to convert your truck to be the most sought-after year of that body style. Think about it, there are probably more "'67" Chevys, "'40" Fords, and "'56" Chevys than there were on the road 20 years ago. And who's gonna blame you for making your classic truck the rarest or at least most sought-after truck possible. You're pretty much guaranteed to get more money for it when you sell it, not to mention feeling like you're investing your money into something worthwhile. One of the most sought-after vehicles in our world is the '56 Ford F-100 Custom Cab. Most agree that the big back window is better looking, and there is no denying that they are harder to come by.
Getting yourself into a big-window Effie just got a little easier thanks to the new big-window conversion available from Goodmark. It is a new metal frame and surrounding sheetmetal, and once all of the spot welds are removed and the cut is made across the bottom of the cab back, the new piece welds in. The cool thing is that the doorframes remain intact, so there is not as much danger with the cab flexing out of whack while welding the new frame in.
World-famous F-100 builder Bobco in Lake Elsinore, California, got their hands on one of the very first of these frames and has since performed about a dozen of these surgeries. Follow along as Marco makes the job look easy and check with Goodmark or Bobco to make your very own Effie a big-window.
Size: Small |
Size: Large |
 The new big back-window frame...  The new big back-window frame for Effies comes from Goodmark and is an all-new metal frame with surrounding sheetmetal. Once installed, only the bottom edge and a few spots on the inside have exposed welds. |
 Before any cutting takes place,...  Before any cutting takes place, several spot welds need to be drilled out. The main areas are down each side of the doorframe. Then there are two where the mount for the dome light attaches to and two more for an inner brace on each side. |
 Marco taped off the top and...  Marco taped off the top and bottom areas where they will be cut. Since it is critical that the cab back has a clean cut and remains straight, a cutoff wheel was used, along with a very steady hand. Extra care was taken around the edges to make sure the inner doorframes weren't severed. |
 Since the top cut is not nearly...  Since the top cut is not nearly as critical, a quick cut was made with the plasma cutter. The cutoff wheel was still used at each end, though. |
 Now the edge of the section...  Now the edge of the section to be removed could be pried off of the inner doorframe. |
 It was time to say goodbye...  It was time to say goodbye to the small-window! |
 With the bulk of the old metal...  With the bulk of the old metal out of the way, it was much easier to drill out the spot welds that hold the back section of the cab to the roof section. |
 Now an air chisel was used...  Now an air chisel was used to pry the last of the back section off of the roof. This area was checked to be flat with a hammer and dolly, and then it and the inner doorframes were ground clean. |
 Marco lifted the new section...  Marco lifted the new section into place and checked the fit in all the areas to be welded. You can mark the cab where the new frame section ends for cutting, but the Bobco method is to trim the section down. This way, the weld is higher up and hidden from view from the inside of the cab. |
 The bodyline around the door...  The bodyline around the door is definitely one of the most critical. |
 This pneumatic flanging tool...  This pneumatic flanging tool was then run around the perimeter of the cab, creating a slight indention for the new section to overlap. |
 Now the bottom edge of the...  Now the bottom edge of the Goodmark section was trimmed down with the cutoff wheel. The end areas were not cut just yet, however. |
 A pneumatic hole punch was...  A pneumatic hole punch was used add holes along the inner and outer edges for Marco to weld to. |
 The length of the roof section...  The length of the roof section got the same treatment. |
 Now the big-window frame was...  Now the big-window frame was popped in for the final time. |
 Starting at the top, Marco...  Starting at the top, Marco attached several clamping devices to hold the sections together before beginning to weld. |
 Finally, the side areas were...  Finally, the side areas were trimmed down to just above the flange line. |
 A few last-minute taps with...  A few last-minute taps with the body hammer ensured there were no gaps between any of the old and new panels. |
 The first welds were in each...  The first welds were in each corner while everything was firmly clamped. |
 Next, all of the spots along...  Next, all of the spots along the outer skin were welded to the doorframe... |
 ...followed by the row across...  ...followed by the row across the roof skin. These are tricky to hit, but Marco handled it with no problems. |
 Finally, the new panel was...  Finally, the new panel was welded to the cab. Marco started by clamping the two every few inches--welding a spot on each side and moving elsewhere. Slow and steady is the only way to keep the panel from warping. |
 Eventually, the entire panel...  Eventually, the entire panel was welded solid. |
 The outside edges are made...  The outside edges are made to be hammered around the doorframe, just like from the factory. |
 Now came the tedious task...  Now came the tedious task of smoothing over all the welds. The inside is fairly easy. |
 The big weld was first hit...  The big weld was first hit with a grinder and then followed with a sanding disc. |
 The interior welds cleaned...  The interior welds cleaned up very easily as well. |
 Here's the wraparound section...  Here's the wraparound section all cleaned up with its first coat of primer. |
 Judging by the perfect matching...  Judging by the perfect matching of bodylines and perfect door gaps, we'd say this install was a success. All that was left was final blocking and paint. Another Bobco masterpiece was in the bag. |