I have a 99 F150 with a 4.2, I want to swap it out for a 5.4. Has anyone done anything like this? If you have do you have any suggestions on how to go about it, or what to expect. Any help or advice will be great. Thank you in advance.

 

it can be done. youre gonna have to replace everything drive train wise. not an easy project but just take your time and dont get in a rush.

 

Not are you only going to have to replace the tranny as well but you would have to replace the computer and harness. You will not just be able to get away with just a tune. Also there is probably some wiring under the dash that is different too. Converting V6 to a V8 in the computer age isn't easy like it was back in carburater days. It's not easy for an experienced mechanic in a shop let alone a shade tree mechanic doing it in his garage or back yard. All in all you're probably better off selling the truck you have and buying one that is already a V8

 

X 2.

It will cost you less and you will spend far less time on it.

Also, if you do make the engine swap yourself, it may be very hard to sell the truck later, even though you have spent a ton of $ on it.

 

double post