Can I install an engine 3.5 ecoboost year 2015 in a truck f150 fx4 year 2012?

I suppose you could but you would save thousands of dollars, weeks or months of trouble and a lot of headaches by selling your truck and buying an Ecoboost F150.

I would almost have to certainly suspect you will have issues with the computer system inside the 2012. You may have to take along the wiring harness and all sensors at a minimum. You can check the part numbers for the PCM to see if they are the same, and if not, take that along also. You will also have to flash the old PCM with new programming is the part numbers are the same for the PCM. FOR's suggestion is best for the peace of mind value alone.

I would almost have to certainly suspect you will have issues with the computer system inside the 2012. You may have to take along the wiring harness and all sensors at a minimum. You can check the part numbers for the PCM to see if they are the same, and if not, take that along also. You will also have to flash the old PCM with new programming if the part numbers are the same for the PCM. FOR's suggestion is best for the peace of mind value alone.