If you can get a 94-96 Ram, B series van, or (if you are lucky) a Dakota R/T with the 5.9 and A-518 OD tranny COMPLETE then the swap isn't too hard. Lots of wiring to interface between the EFI and the old dart harness. You will need to have an electric fuel pump that will put out at least 40 PSI, A Schumaker engine swap motor mount set, and a lot of patience. Other than the tranny its a bolt in for the engine and a relatively easy swap for the electronics.
The tranny is the problem. If you go with an older tranny then you can pretty much forget about using the factory EFI setup since the ECM needs input from the tranny to work correctly. The advantage to the newer tranny is the OD and TC lockup. I have 3:23 gears in my dart and cruize at 70 MPH at 2000 RPM but around town it is the same as a 727. Problem is that there is no way to correctly shoehorn in the tranny and get the proper engine angle, etc., without doing the tunnel mod since the tailshaft of the 518 is much larger in diameter than the 727. I have heard of people using the stick shift ECM to get away from the problems with the ECM vs. tranny input (basically VSS signal) but I haven't tried it.
Larry
Larry