Idk if there is any info on it at least in the tech library. I'd searh around on the forums. If i remember correctly AllanD posted to a simular thread on a simular swap. If I can find it later I'll post it up.
You CAN do the swap. It's just how patient are you? How sick and twisted are you to put yourself through this self torture???? OBD-II is gonna be a picky management system. Your gonna need every little sensor and system that the orig. vehicle had on it. That means every sensors from the fuel tank to the exhaust or you're gonna get a CEL. (EVAP, VSS, HO2S)etc.) Not to mention a functional 16pin test connector.
I think the hardest part of the swap will be wiring the engine compartment back into the dash wiring. For gauges, and the OBD-II test connector. That's going to be a nightmare. It'd be a must to obtain wiring diagrams for a 2002 sporttrac and 88' Ranger. The easiest plug and play you could have would be to perform some firewall surgery and retrofit a 95' up Ranger dash in. The HVAC system is different, and the bulkhead(firewall) is cut out differently. Yet I do believe this will get you the best results.
Now that I've scared you with the 4.0 OHC swap, may I suggest to you a 4.0 OHV swap? OBD-I, an explorer harness, and with your 88' the engine compartment to dash plug should be compatable. My suggestion would be to just find a 93 or 94 Explorer and just swap everything from one truck to the other. Maybe even including the dash as it shares(IIRC) the same HVAC system.
AllanD may weigh in on this soon enough.