This gets discussed on slantsix.org from time to time, but I wouldn't try swapping Jeep 4.0 hardware onto anything but an older AMC straight six. Here's why not.
1. The Jeep engines used an oddball crank trigger; you'd have to custom machine one to work on anything it doesn't bolt to.
2. There are almost no tuning tools for the factory ECU. You might get away with this on a stock slant six, but on a turbo motor you're going to need some way to hack its fuel and ignition tables.
3. For a turbo motor, it's easy to run out of injector size when (2) prevents you from retuning it for larger injectors.
The only OEM EFI engine management I've seen successfully transplanted onto a slant six was off a GM V6. If you really know OEM computers, I suspect it would be possible to get the EEC-IV system on certain Ford V6s to work on a slant six, or the Bosch Motronic system used on BMW slant sixes. There are at least chip burning tools available for the OBD1 Motronic and EEC-IV, though I'm not sure if there's enough support and documentation to make them work on wildly different engines or not.
