Okay so I have a 2002 f150 2wd crewcab the truck has the 4.6 and is pretty high in millage and me and my dad were thinking about doing an engine swap with a 03/04 cobra motor because there both a 4.6 motor. I know I new to replace the rear end and maybe the tranny and computer. But I was wondering if anybody has seen this swap done and if I would need to swap the wiring harness or if the computer would work with my wiring harness. I'm only 16 and its not my everyday driver but I still will not start the project till I have everything I need to do swap. So if anybody has any input or an opinion on this fire away I need every bit of info I can get. Thanks! soo I've decided to forget the cobra swap ive done some more research and I sounds awful and most of you agree with me I think. im just going to buy a donor Harley Davidson f150 and do that swap

 

You are going from a 2V 4.6 to a 4V 4.6 with an Eaton Supercharger on it. Nice motor...fur sure...400 hp. conservatively. Where did you get the motor? As you stated ...computer will have to move with it, and move the tranny with it. The Supercharger will create some fitment issues, but should have lots of room to mount stuff. I don't think the fuel pump will handle it...but that can be switched. Exhausr issues lining up, driveshaft...I dunno' man....I can see a host of curveballs here. I was 16 once also, so I don't want to discourage you. But back in the 60's to swap out a 283 to a 400 small block was mounts and few minor things...different world these days. Good Luck....would be one heck of learning experience for you.

 

There is a big re-engineering job here.
Unless your up to it, don't even begin the project.
You become the expert after the fact.
No shop would touch it, otherwise.
Good luck.

 

I switched motors in my 97 f150 truck from the stock 4.6L to a built motor using a cobra block and didn't have any problems with fitment.

 

It will be a little while before I do any swap I am just seeing what I can do and what I can't. And I'm not one of those stubborn oh I can do anything people. I will probably find a wrecked Harley and just swap all that over because everything will swap over with slight fab work. I doubt ill do the cobra swap because I'm not a fabricator and I'm just starting out. Thank you guys for your opinion and help! Any of you have any say on the Harley swap?

 

I would look into a donor Lightning with a blown 5.4L.

 

Well I would go lightning but my truck is 4 door like the Harley so the Harley will have the drive shaft and everything the right length or will my stock drive shaft handle the extra power?

 

I'd go with the 4.6 dohc cobra motor because the extra valves give large gains. There are some very respectable 2vs around, but not without a lot of $. You can go with a dohc motor out of a 96-98 cobra and add a Vortech, Paxton, or Procharger... Endless possibilities but 4v is way to go IMO

 

I'm wanting an already supercharged motor don't have a lot of money to do an after market super charger after I do the swap I'm going to start saving for better internals like cam and lifter and heads but I'm not going to go crazy just light work for a little extra hp

 

I think you're going to find it a fairly straight forward swap.

The motor drops right in, will accept F150 motor mounts.
Transmission, bolts right up.
Driveshaft will go right back in, though you'll need a real driveshaft (Dynatech, Mark Williams, etc.) to avoid breaking the 4R70W extension housing or walking the extension housing bushing out over 100 MPH.
F150 A/C lines SHOULD work
You'll need to modify your wiring harness to work with the '03 Cobra low mounted alternator, and most 4V coils are reverse polarity so you'll probably be re-pining your coil connectors IF you use the F150 engine harness. You'll also have to greatly extend your harness at the coil, due to their lower placement on the 4V. You'll likely also have to modify the harness in order to reach the 4V TP sensor, IAC motor, etc.
You MAY run into issues with throttle cable and cruise control cable length.
You'll need 4V coolant hoses and thermostat housing.
You'll need an 8-bolt flexplate, since I'm assuming you have a Romeo 4.6 which uses a 6-bolt crank.


All in all the swap is VERY doable and won't be all that bad, but I'd prepare yourself for snags here and there.

 

If you dont have deep pockets dont start it, you said you wanted to change cams, that is $1200, for just the cams, not counting the valve springs, retainers, new timing chains, for cams you will probl be at $3,000. i say in the swap you will be over 8 grand after all is said and done. if i was you i would find another 4.6 for your truck, and just put on a small supercharger like a nova and run light boost.

 

I understand what cams and everything costs. im just going to buy a donor Harley f 150. and keep it out of the truck for a while and do the motor work and do the swap a few months afer