i own a 1999 ford f-150 that the motor started kknocken real loud.and when i drained the oil about a gallon of antifreeze come out.rather than try to fix the problem with that motor i bought another truck for cheap.it was wrecked but the motor was supposibly good.its a 1997 for f-150.so i started to make the swap from the 97 to 99.the 97 has several more vaccume lines and different size injectors than the 99.and the electrical plugs on the injectors are different than that on my 99 wiring harness.a mechanic told me i had to swap the whole harness so my computer will read the motor correctly.do i need to swap the heads??or can i simply cut and splice the injecter plugs to fit from the two wiring harnesses???i really dont want to have to change the entire electrical system with the brain and all.b/c id have to swap the vaccume system too.money is definately an issue here as well.is this swap even possible and if so what all has to be swapped out????the mechanic here told me to swap the complete electrical harness.but it wont convert due to the injecter plugs,and i cnt find which plug on the 99 harness goes to thermostat.i talked to the mechanic about it and hes worried if i cut and splice the harness to make one it could burn up the brain in my truck.he wasnt really sure what would happen.both motors are a 4.2.but the 99 has a sensor on the back left side of the motor under the head,(when looking at the motor from the rear)what does this sensor due?everything els seems to match up.besides a few vaccume and electrical plugs.please help.

 

Please use spell check and try to type shorter sentences. It makes it easier for us to help you.

Do NOT splice the harness, use your original 1999 harness and everything that fits it.
You don't need to swap heads.

You need to remove all the "different" parts such as the fuel injectors to convert the replacement engine from your old one. Use a digital camera if you can get one to take pics of everything as you go.

The injectors should have a different electrical connector but are the same size on the end that goes into the engine. Remove the injectors GENTLY so you don't damage the tips. If you crack any of the injector seals get new ones, they are cheap.

I put a 2000 engine into a 1997 which is basically the reverse of what you are doing. Just take your time and be careful with the electrical connectors.

So long as you have a sensor for every connector on the 1999 engine harness you are using, you are good to go. I removed the plastic inner fender wells for easy access to the bellhousing bolts, engine mounts, and exhaust.