OK, a reply from a guy that is doing exactly what you are talking about.
I am bolting a '94 360 Magnum engine into my '85 Ramcharger and pulling my sick 360 LA engine out.
I scored the engine complete with ALL accessories for $550.
I was over at 100K miles but I removed the oil pan and found it extremely clean, not a bit of sludge anywhere. The compress test was right on the money on all cylinders.
The beauty is that is nice tight single serpentine belt drive on the accessories. Making the EFI work is a future project and it doesn't fit into my time frame of having this thing back on the road by the spring.
So, I am removing the EFI barrel intake and replace it with a MP carb intake.
What you want is the MoPar Performance P5007381 intake.
It is a dual plane stock performance intake. Don't go with the Edelbrock RPM made for this swap, it is a 1500 RPM + intake made for hot rodding with higher compression and a bigger cam, and a higher stall converter. Not what you want for a low end torque making 4x4. I plan to top this with a rebuilt ThermoQuad carb. That will give me good mileage with excellent low end torque because of the small primaries.
You will need to swap your old distributor back in because the EFI one doesn't have vacuum advance.
Other than that it is a pretty stright forward bolt-up.
If you can find a Magnum with all accessories in tact jump on it! The way they bolt up is far superior than the old "guess a bracket" LA engines.
OH, you will need to swap to a electric fuel pump since a late model Magnum doesn't have a provision for a mechanical one. I recommend a Carter P4070. Summit has them for $60. I use this one on the last couple hot rod cars I had and they are extremely reliable.
OH, and to be more on target relating to your fuel injection question, EFI is ideal for off roading. It doesn't have the harsh angle of attack problems that a carb does, it is superior in low end torque making and throttle response, and it gets better overall mileage, and since it in electronic system relying on several sensor inputs it is self tuning. Not bad at all.
The problem is adapting one of these things to a older carbed truck is a daunting task. Even if you can score all the bolt-on parts to a late model EFI setup the system will need several inputs from sensors that your vehicle just does not have.
Now, bolting on the extras so you can adapt it to your older vehicle that much of a problems BUT, factory EFI setups don't like to depart from factory perameters. If there is a problem anywhere it will run like crap. If it isn't a project that you are willing to invest many, many, hours in getting all the bugs worked out you need to swap to a carb setup.
Of course there are aftermarket EFI systems you can buy that are bolt up. But they have a $2000 price tag and I am one of those guys that doesn't have that kind of bread to spare.