Originally Posted by 79rocket

You can use the harness and ECU from the 4.6 truck, just leave it in, but you will have to have the ECU reflashed (tuned) to the 5.4 engine. The 5.4 will have a coil over plug (COP) ignition system, but you can use the coil packs that are in the 4.6 truck if you have them, if you already have COP ignition then you're set. A/C compressor can be reused, but check if the donor engine and the 4.6 have the same number of ribs on them. Motor mounts are the same. I can't help you out with the torque converter question, as mine was a standard, but if you read back through this thread a few times, all of your questions have already been answered through other people asking them. Good luck.

Originally Posted by mmacak

Im confused just got another lifted f150 had a 99 it had 5.4 im looking to swap in a 2000 f150 4x4 lifted with a 6" fabtech lift
it has 4.6 i wanna swap in a 5.4
i understand following


-can use same tranny (do i need a new torque converter?)
-do i need new mounts for engine and i know from what uve said i can use a 5.4 from a 97-99 f150 with 5.4 triton can i go up to a early 2000??? just wanna make sure i get correct motor


-electrical wise can i use the same mine has the individual coil packs that go over the spark plugs.....do i need to do anything to wiring harness to make it work?

- can i use the air intake
-can i use the a/c compressor?
-can i use evrything on top of motor just swap in the motor bassically ???throttle body ect???? tell me all u can please greatly appreciate it

My truck is a 2000 ford f-150 has the 4.6 v8 its 4x4 it was manufactured in 12/99 so im guessing it has non pi-heads can u tell me what pi means ?? this is first motor job ive done ive done everything else i dont take ionformation from book or writting very good ....so i have to ask several questions i wanna make sure i get all i need so i order and get the stuff i need can u tell me exactly what i need make me a list if possible id greatly appreciate it

anyone in the indiana area willing to help me lol be awesome but if not thats okay too i can figure it out and do it

Originally Posted by mmacak

okay thank u very much u have been a great help this makes more sense easier to understand all i need is a motor i have on top coil packs so everything shoiuld match up fine

Originally Posted by JMC

Notes for 4.6 to 5.4 swap Part 1 Revised 28 January 2011
Application: These notes cover the F-150 from 1997 to 2004 Heritage model years.

Cylinder Heads: The following info applies to the F-150 and not any other vehicle engine.
4.6 Engine: The 4.6 engine had Non Pi Heads from 1997 to 2000. The Pi heads were introduced to this engine for the 2001 model year.
5.4 Engine: The 5.4 engine had Non Pi Heads from 1997 to 1998. The Pi heads were introduced to this engine for the 1999 model year.

Exhaust: The collectors on the exhaust manifolds are set at different angles and locations. The 4.6 exhaust might not bolt up to 5.4 manifold. You may need to have a muffler shop modify your 4.6 exhaust to match up.

Ignition: All 5.4 engines use Cop ignition. . 2000 and later 4.6 use COP ignition. 1997-99 4.6 engines use coil packs. It is easier to wire your 5.4 using the harness from the 4.6 and use the 4.6 ignition coil packs if applicable. If you use the 4.6 Coil pack ignition you will have to fab a bracket for the driver side coil pack.

Engine harness: To use a 4.6 PCM to run a 5.4 engine: The IAC harness must be relocated to the rear of the throttle body elbow. The oil sender wire on the 4.6 may be too short so measure or test fit the harness to see if it must be extended. All 97-00 and some 2001 4.6 engines use some sort of intake manifold runner control valve. Remove it from the 4.6 and plug it into the 4.6 harness and bolt it to the engine some where out of the way. Note; you can get a tune to remove its function and eliminate it all together.
All 97-98 4.6 engines use an Engine Coolant Temp sensor (ECT) and an Engine Coolant Temp sender. By the 99 Model year the ECT was dropped in both the 4.6 and 5.4 harness as the Cylinder Head Temperature sensor (CHT) was used for the PCM to monitor coolant temps. None of the 00+ 5.4s use ECT sensor or sender. Some of the 99 5.4s still use the sender to feed info to the instrument cluster. You will have to tap the intake manifold crossover pipe to fit the sensor(s) if your 4.6 has them and the 5.4 doesn’t.

Transmissions: the 4.6 and 5.4 have the same bellhousing bolt pattern. That means that all the transmissions will bolt up. All the 5.4 engines have 8 bolt crankshafts. Some 4.6 engines (ROMEO ENGINE) have 6 bolt cranks. You will need the flex plate from the 5.4.
Manual transmissions: If you don’t have an 8 bolt flywheel a flywheel from a 1997-8 4.6 Windsor engine will work. As it has 8 bolts it will bolt right up to the 5.4 crank. Remove the flex plate spacer and install a pilot bearing from a 4.6.

Special note about the different automatic transmissions and their respective harnesses. You cannot run a 4R100 transmission with a PCM that had a 4R70W transmission and vice versa. The transmission harnesses are different and will not plug into the different engine bay harness. The control functions in the PCM are not compatible so the transmission will not function properly.


Torque Converters:
4R70W
ENGINE............Stall Speed............Multiplication
4.2..................1978-2330...............2.3:1
4.6..................2105-2505...............2.3:1
5.4..................1830-2190...............1.9:1

4R100
All Engines......??????....................2.2:1


If you swap a 5.4 into a 4.6 engine bay and use the 4.6 converter you will multiply the 5.4's torque at a higher rate and at a higher stall speed which will put the torque at the transmission input shaft close to the limit if not over the limit of the 4R70W. The 99+ 5.4 produces 350 ft/lbs of torque. 90% of that is available at 2000 rpm. The stall speed of the 4.6 is above the 2000 rpm range so more than 90% is available. 350 ft/lbs x 2.3(4.6 multiplier) x 90% is 724.5 ft/lbs.