I've got a 98 F150 with a 99 Expedition supercharged 5.4. I think it blew holes in a few pistons a while back. I was running 10 -15 lbs of boost and something went wrong. Anyway, it's down and I'm looking at swapping a DOHC out of a 93 Mark VIII into it to get it back on the road till I can go through the 5.4. Has anyone done a swap like this and if so what problems will I be looking at. My main worry is the wiring harness. Will a 5.4supercharged ECM and harness work on a non-supercharged DOHC. I've read where the motor mounts and transmission should be the same. Any info would be much appreciated.

 

arent you suppose to build up the block before you out 10-15# boost. pistons.heads etc...?? i lincoln 4.6 has different intake etc... you want a truck 4.6 remember it has to pull 5,000 lbs around.i have 2 4.6 96 crown vic police and 97 f150. its night and day, crown vic will get up and go light them up off the line. truck not even close. but no way are you going to pull 2,000# trailer with a lincoln, crown vic 4.6. torque is the name of the game

 

Off-topic, but...
Wow, 10 - 15psi is a pretty big range.

10psi is generally safe...15psi is 50% more and I don't think its really considered safe on stock internals.

 

Believe me this truck will not be towing. Currently running 4.10 posi with tricked out tranny. I just need a powerplant that will allow it to move under it's own power while I find out what failed in my 5.4. My questons are whether the DOHC would work without alot of custom work.

 

I've considered swapping the DOHC 4 vale heads onto a 5.4 block and everyone seems to be trying to discourage me.

now is the lincoln blackwood faster than a 5.4 powered supercrew of the same year??? like you i do not care about pulling trailers (i have an F-250 for that stuff)

#1: I know the wiring harness needs to be modified to accept the DOHC ingnition and injectors

#2: I'm sure Troyers can get you a decent tune but you probably shouldn't run your old tune

 

I've read aout putting the DOHC heads on a 5.4 but wondered about intake compatibility. Which would you use the 4.6 or the 5.4. Has anyone pulled a wiring harness off one of these before. How much trouble is it?