This is a hands on, how to, picture course on making a big window truck out of a small window one. This job wasn't easy, but is do-able. The toughest part of the job is making the cuts on the two tops the same. The measurements or cut lines are the same, but cutting the two exactly the same is impossible. Thankfully, grinders do a marvelous job of equaling the two. Give yourself a little extra metal on one cab or the other.
I bought a nice donor big window cab, with doors, and proceeded to graft it on my truck. This shows my idea of where to cut the front posts. I got some input on this from different folks, but I think this was the best for me. In my mind, if the two cut lines didn't match up too well, I could trim without hurting anything. The second picture shows the cut.
This is the line on the back of the cab. The picture is just for illustration only, it isn't the donor cab. Inside the cab is a band that helps support the window and my cut line was just below this. This band is also a mount for the original headliner and window side coverings. I saved it to help support the new window. If I cut that band out, I think the back of the cab would have been a little on the flexible side. The second picture shows the cut.
This is Korey, my good friend, that is cutting the back of the old cab with a sawzall.
The new top placed on the old truck. We left the old doors in place to see how everything would match up. Another reason was to help support the new top as you weld it in place. Later on, we swapped out those doors for some good ones off the donor cab.
WOW! I like it! Old top verus new top comparision. You have to weld at intervals of 3-4 inches so as to not produce a lot of heat and warp the metal. Then you keep going back and rewelding next to the old welds until all the metal is completely welded.
This is a picture of inside the cab that has been welded and sanded and then body putty applied and sanded. If you look close you can see the band I was referring to.
This one shows the final job on the outside of the cab. It looks great! The picture doesn't show the welding and grinding involved. To get a smooth look, you need to do a lot a longboard sanding to find the high and low spots and deal with them. Wet sanding is good too. If you think it looks pretty smooth, just spray a light dusting of primer on your work and longboard it again, and you would be surprized to see there are still some waves. After much more of this you get a wrinkle free job that looks like it came from the factory that way. I always thought body shops overcharged for their work but after watching Korey do this job for me, I have a new found appreciation for these guys! This truck will not be painted for a while yet as I'm still doing other things to it. But eventually it will be painted and I'll pass those pictures on to show you the final result.