The Ranger splitter would work perfectly in the sense that I already have a complete T19 and clutch configuration as found in a stock diesel Scout. It would not work as is, however, because the input shaft of the Scout T19 would be too long and the input shaft of the Ranger splitter would be too short. I would have to call them and find out if the two input shafts can be swapped for each other. Its plausible. If so that would be worth the $1300 to me, since I would benefit greatly from "inbetween" gears. It would also still be much cheaper than an NV4500 prepped to install.
I still don't understand how you are going to install the Clark transmission behind the SD33. A SAE3 adaptor will not bolt up to the SD33. SAE4 and SAE3 are not at all the same. The only SAE4 to Mopar big block adaptor I know of that exists is the one found in CJ10a towpigs. After you have that, what pilot bearing, flywheel, and clutch assembly are you using? The starter attaches to the Towpig adaptor ring, so it will need the original SD33 flywheel to have the notches to engage with if you use the Scout starter. If you use a Dodge starter and flywheel, how will they mate with the SD33 and is the depth correct? Will the adaptor ring leave enough room for the Dodge starter?