Have a 99 f150 with 500,00 miles and it recently developed multiple missfires along with a bank 1 too lean code and cant seem to get it fixed....have changed everything except injectors. when i changed plugs number 3 had aluminium all over it. its also had some kinda chatter in the motor for the last 4 years and along with smoking randomly especilly after idling for a few minutes it would bellow smoke for a few seconds then clear up. Transmission has also been acting up for the last 2 years so its getting replaced also.

Anyways its time for another motor and navi 5.4s are easy and cheap to come by so thats what i wanna do. ive read multiple post from this fourum and others but info is scattered and its kinda overwhelming so im just trying to get my ducks ina row before i start.

1. 03-04 navi 5.4...does it matter? is there anydifference between the 2 years?

2. 2v 5.4 trans....Its sposedto be a little beefier right? also use the 5.4 tourqe converter?

3. Keep the COP and use the navi harnes or use my harness and extend sensor wires as needed and keep the 2 coilpacks?

4. I need to use my oilpan and pickup tube right?

5. Headers....no navi long tube navi headers that ive seen....have a set of 2v 5.4 headers..will they work/can they be made to work? I have catless true duals dumping in front of each rear tire atm. If not ill just use stock manifolds.

6. I want to replace the entire front clip.....its a little beat up from catchin a couple of deer last year....would it make the swap easier with everything off? if so ill go ahead and pull the front clip off and replace it at the same time....if not ill worry about replacing that later.

7. Anything paticular i should replace on the navi motor while its out? I wanna replace plugs/valve cover gaskets/front and rear seals/oilpan gasket/belt/ idler and tensioner pullys. Is there anything im missing?

8. Should i upgrade to lightning MAF and injectors and pump or not?

9. Egr delete...yay/nay?

10. I will have it dyno tuned....do i need to get a tuner? can the god awful useless anti theft garbage be programmed out? Its been acting up randomly in the last couple of months.

11. Have i covered all the bases? im sure im forgetting something...if so plz tell me and any help or input would be awesome.

 

WOW 1/2 million miles....congrats

can't really answer much, but keep digging. Off hand I would suggest that you just get a donor vehicle and use as much as you can from that engine , trans and wiring harness. As long as you stay with 2v engines it shouldn't be too bad. Somewhere I thought that the Navigators had 4v engines ...maybe not? or in different years?

Have you looked around in YouTube?

 

The 04 Navi did in fact come with a 4V - replaced by the 3V in 05.

 

All original except plugs/wires/belt and alternator Yes the navi 5.4 is 4v. Quiet a bit stronger than the 2v 5.4 which is why im going that route.

 

With going with the 4v version...I would think that the headers are not going to play nice at all. Thinking that the port spacing is different?

I'm sure its been done....maybe you have seen these maybe not? a quick search here>>>https://www.f150online.com/forums/v8...avi-heads.html

 

Yeah ive read most of the threads on this forum i could find lol and i had a feeling they wouldnt but it was worth asking.