Started the conversion, on the 2003 f150 4x4. Removed the tired 4.6L engine, started getting 5.4 engine ready to install, the motor is a 1998 winsor from what I could tell so far the injector connections on the harness were different and the od connection, easily fixed up, lots of soldering and heat shrinks, exhast angles were all differant, 2 wheel drive motor I had to re/re oil filter mount to allow front diff....compatable, easy. Throttle assembly re/re compatable also, removed intake to re/re a temp, knock, ground sensor bolted to the block. Now I'm onto the flex plate........4.6 had 6 bolts mounting it to the motor, the 5.4 needs 8 bolts,

A question I have now is about the tranny issue....it's a 4R70W trans, and because it's a 2003 I don't think they ever mounted this year trans to a 5.4, therefore problems may include....the computer campatabity....does the trans have it's own or does it share the main truck computer, I have the 5.4L computer also for the truck. I also need to know about the balancing....are all years balanced the same for the flex plate? should I get the 2002 flex plate for the 5.4? it should have a bolt pattern, thanks ahead of time for the help guys

 

I cant help with all your questions but I do know that you need to leave the stock 4.6 computer in the truck in order to operate the transmission!
I believe the 98 5.4 came with a e40d trans , so the 5.4 computer you have will not operate the 4r70 correctly.
You can have the computer tuned to run the 5.4 motor but you cant have it tuned to operate a different trans.
I found the out when I put a 4r100 in my truck. I had to go to a Lightning computer to make it work.

My 03 5.4 came with a 4r70w but there's a difference with the 4.6 and 5.4 torque converters and there may also be internal differences.

I hope you got a good deal on the 98 5.4?
Probably should of went with a 99 or newer 5.4
If your going through all the trouble of the swap at least you would of got the extra power of the PI heads and intake.

 

great info, thanks....I'll look into the dealership tuning the computer, hope I don't need to buy a tuner....I would say I did okay, paid $800 CAN for the engine, said to be completely rebuilt but it's so spotless that it would make a great kitchen table....there is also still paint on the pully's so I know they have barely anytime on them. Still looking for the 8 bolt flex plate tho

 

It's a shame you live so far away,
I have most of that stuff out of my 03 just collecting dust...lol
8 bolt flexplate,5.4 4r70 torque converter,stock computer.

Sounds like you got a great motor!
Keep us updated on the install and let us know how she runs when you get er going.

 

it's a shame you live so far away, looks like about an 8 hr drive each way, I wonder what it would cost to ship up here lol