I've done just about the same exact thing, but under the main cab of the truck where the I-4 engine was. Currently my XL is 4 studs above the drive shaft leading to the center differential. The only issue I'm having is coming up with a gear combination that is 4 studs tall and 2-3 studs deep that fits and doesn't involve 8T gears stripping. I can lower the XL down so that it's 3 studs above and run a 16T-16T. I can't use an 8T-24T at this spot as this interferes with the steering axle, and I would need to do something with the front PTO as well, as the XL would now be in its way. Is anybody doing something similar? I'll try to get pictures up later this evening.