I have a 1997 ford f150xl with the 4.2L v6 5speed. It has 114,000 miles on it . Last year I was on the interstate and it started to ping and knock i realized it was runnning hot so I suddenly pulled over but it was to late I had blew a head gasket and warped the heads also i had to get the crank turned and new bearings. I had the whole engine rebuilt .Well 10 months later i am back to the same thing.I am so sick of this motor I need a 4.6 or the 5.4. My question is how difficult is it to switch from a 4.2 to a 4.6 or the 5.4.

 

Well to start with, you'll need the motor. transmission aren't the same, so you'll need that. Motor and transmission mounts. Wiring harness and computer. Might be best if you can find a wrecked donor truck, so you can have access to all of the little miscellaneous parts.

 

I was interested in the same thing. I know about the transmission and engine itself but would the computer be that difficult to install? I'm curious if all of the other little parts, O2 sensors, MAF sensor, EGR would just need to be stripped off of the donor motor. I am assuming so. The deal for me is that I can't find anywhere on the net where someone did perform an engine swap to a 4.6 or 5.4

 

the cost of the motor + trans + all other things you'll need along with install, it makes more sense to use that money for a downpayment on a new 5.4

 

fordfreak,

You will need the 4.6, don't use a 5.4 there is too much stuff to change and mods to fab. You will need everything from the 4.6 beginning at the MAF and ending at the exhaust manifolds. The motor mounts, PCM and engine wire harness from the 4.6. If the donor motor doesn't come with sensors you will need them too. Make sure the motor comes with a fly wheel not a flex plate. You should use the new style 4.6 clutch but you could get away with your 4.2 clutch.. The trannies are the same. Interesting project. Let me know how you make out. Oh, don't forget to up grade the rad.

Regards

Jean Marc Chartier

 

I am pretty interested in doing the same thing. Except my idea was less than legal...Anyways, i have a manual and i want the 4.6 V8. me and my friends are now starting to work out the details to see if it is possible, and how much it would cost. when we get everything figured out, i will give ya a hollar.