Getting the engine to physically fit in the vehicle, and attached to a transmission which is connected and working, is less than half the battle when it comes to an engine swap - and it's the easiest part to get completed. The more difficult and far more time-consuming part is the wiring, plumbing, and other connections necessary for it to run. You're talking about converting to FI, which adds another aspect of difficulty to the project, as you'll need to redo the entire fuel system as well as adding the ECU and all the associated sensors and wiring to make the FI function.

If you've got the time, patience, and money to stick it out until it's done, go for it. Plan thoroughly beforehand though, or you'll be selling your partially completed project truck for a serious loss in a few years when you get tired of seeing it sitting around and rotting away.