Being new to crawlers (hopefully, I'll get stop saying that sooner, rather than later), I don't know if this is even a possibility (and, if not, so be it)...but, looking over my Capra, an idea popped into my mind. Before explaining my idea, you have to understand I'm a professional chauffeur, so dealing with stretched vehicles is something I'm sightly familiar with.
Anyway, with stretch limos, they cut the vehicles in the middle, and "extend" by adding additional chassis & body in-between. Granted, with the Capra, the motor & transmission are located in the vehicle's middle, but a slight chassis & tube frame "stretch" should be possible...although, the amount would be fairly minutes. Now, don't take my "estimated measurements" literally...actual measurements would need to be taken...but, I was looking over my Capra, and, based on the amount of up/down movement of the front & rear driveshafts, I'm guessing the transmission could be moved up to approx 1.5cm back without the driveshaft hitting the front of the skid, and the same for the rear, if the transmission was moved forward...both without cutting the skid in the areas around the driveshafts. If someone was willing to cut/Dremel away material from the skid, if bet the distance could be up to twice that amount. If it were possible to move both by that amount (3cm at each end), that would mean the vehicle could be stretched, from the middle, by up to 6cm (just under 2.5").
Now, here's the part that I don't know whether, or not, it's even a possibility. Regarding the tube frame, I can see the possible ways of stretching it. For those familiar with working with tube frames (I'm not), you could cut the entire frame in half, and then add tubing pieces (of the stretched length) to each cut member. For those who have no knowledge/experience working with running, if a second frame was purchased, the "midpoint" of both could be determined, with one being cut in half 1.5" behind the midpoint, and the other 1.5" in front of the midpoint. Then, the two half-frames would be merged together, creating the desired 3" stretch. If a shorter stretch were being done, just adjust the cut points.
Switching to the skid, again, I see (again a work absolutely no knowledge in modding crawlers) two possible options. The first would be a second skid, going through the same process described above, and then drilling new mounting holes for the transmission. The second option would be to 3D scan the skid, stretch the model by the desired length, adjust the files to include a U-shaped 'cutout' where the front/rear driveshafts extend, and 3D print a new, longer skid, again drilling the transmission mounting holes where needed.
Finally, in regards to the driveshafts, themselves, it's just a matter of determining the lengths needed, buying them, and installing them.
Again, the Capra is my first crawler, so I (obviously) have no experience in modding crawlers...but, I do have experience in modding other vehicle types (including Slash & Rustler 4x4s). As a matter of fact, I'm just finishing up a project on a Rustler 4x4 that, among other things, includes utilizing front XO-1 shock towers on the front AND rear of the Rusty.
~ More peace, love, laughter & kindness would make the world a MUCH better place
