I start with a measuring tape. But please don't do that. You're dealing with two unibody cars. If you don't understand what difference that makes then you REALLY shouldn't attempt this.
Photoshop is the easiest. If you want to do it for realz you need some serious metal work skills. Start by serving a 4 year apprenticeship in a body shop to learn the basics and work up from there. Sorry I can't teach you how to do this in 2 minutes, it is about the hardest thing you can do in bodywork short of making a whole car from scratch.
________________________________________________ Tinbender, It was Nash that had the unibody not Hudson. From Bold Ride site: The major innovation of the Hudson line was the step-down design. While traditional body-on-frame cars forced their p***engers to climb up to enter them, Hudson designers placed the p***enger compartment down inside the ch***is, and a sturdy perimeter frame encircled the p***enger compartment. Jerry
take a look at my build thread on my F1 pickup...I used 48 chevy sedan doors. @ fronts and 2 rears. It's a lot of work even for me , and I've been doin metalwork for 23years. like mentioned above ...start with photoshop.Could save you a pile of grief.
Sounds like you have a good understanding of the structure. The entire body deals with crash energy. You have to be careful when altering the top, and the pillars. Without the correct reinforcement you can severely change how the body responds to an impact. They also have to take more stress and vibration during normal driving. Not saying you can't, you just have to consider the design differences. 36 vette, your right I was thinking Nash. Nonetheless, I think a Falcon wagon would be a poor choice for a project like this.
Talking completely out of my **** here.... but I did get bored and watch some home hydro forming videos on YouTube last night.... 1" square tube frame built to line the top of bed, back of cab on the Ranchero. Temporarily Brace the ever loving jebus out of that. Weld up a triangular sheet metal box across that, including one to close off the cab/bed portion, that bit will be cut out later. Pump it up with a pressure washer to make it rounded. Cut off the unnecessary parts, use a ports power or such to push your frame back where it belongs, fix the flaws that have appeared in the skin. It might work? At the very least would be an awesome tech thread.
This stuff always works easy in photoshop because scale can be adjusted with the swipe of a mouse, not to mention the elimination of that pesky third dimension when it comes to compound curves. If you're going to mock this up in a computer make sure you've got a measuring tape extended to an even foot in all of your pics so you can at least get close on comparative size. Make sure the tape is sitting in a relative spot in the photos of both cars like the same corner of the bottom of the windshield etc. If you can get a couple of model kits or die casts all the better to dremel them into bits. OR if you want to just start cutting and welding think about boning up on your metal shaping skills. The world is much more critical now (probably including you) when it comes to custom body work. A look through any old van mag from the 70's will show some of the hideous looks that were celebrated just for the sake of being "custom". That usually wont fly now. A good custom will be the result of good vision and excellent execution skills and there's lots of people out there with both now.
Interestingly enough that you are thinking about modifying a Falcon with a completely different style top,others have thought outside this same box. Remember the Holman-Moody falcon? HRP
save time and frustration and get an early AMC Marlin they look almost the same from the factory and lots out there for sale