Do you have a 2.0(g63b) or the 2.6(g54b). From everything I've read and from a few people I've talked to the 2.0 and 2.4(fuel injected 4g64) have the same heads. I know FOR A FACT they use the same valve covers as I swapped my polished one from my 2.0 onto my buddies 2.4 and its common knowledge they use the same exhaust manifold
2.0 intake gasket

2.4 gasket


So I looked up the intake manifold gaskets and they BOTH use the same intake manifold gasket at the head. So what this means is IF YOU HAVE A 2.0L(g63b) then YES you can swap it to fuel injection.
What you will need from a 2.4L(4g64) truck:
intake manifold and all related accesories/sensors/injectors/fuel rail. You will also need the MAF(mass airflow sensor) and the ECU and engine wiring harness. Also the o2 sensor. There might be an item or two I forgot.

That should convert your truck to fuel injection, unless you have a g54b(2.6l) in which you will need to find all those items from a mitsubishi starion/conquest with a (tbi)g54b