Yet another 5.4l v8 to 6.8l v10 thread

Hi All! Our 2012 Expedition threw a rod back in April. It has a 5.4l 3 valve v8 triton which is obviously deceased.

I'm toying with two very different ideas: buy a 5.4l remanufactured crate engine and swap out the old with the identical new; or consider doing a swap to a 6.8l v10.

Option 1 is obviously the safe and easy route.

Here's the details for option 2, and I need to know how problematic it would be, what all I would need to replace, etc. I can get a low-mileage (48k original miles) 2002 F250 superduty with a 2-valve v10 Triton, 4r100 transmission, transfer, case, wiring harness, etc. for less than the cost of a 5.4l crate engine. That's a 10 year age gap- going from a 3v to a 2v, but also a 6 speed automatic to a 4 speed automatic. From what I've read in other threads, the engine itself should fit in the space provided no problem. So I need to know a) will the transmission fit without modification? b) will the angle of the exhaust manifold from the F250 make it incompatible with the Expedition leading to the exhaust system running into the new components? c) will the wiring harness from the v10 be compatible with the Expy or will I need to swap dash cluster as well? d) engine mounts and tranny mounts will be moved over or replaced with new, but what else should I replace if I go this route to ensure that it's good to go? e) What issues am I potentially overlooking?

At the end of the day if I can pull off the v10 swap for a similar price to a crate engine and get the extra towing power, I would like to do it. But it's much more extensive a project than my previous endeavors, so I don't want to overlook anything. And if this is just something that's not realistically possible considering the differences, I'd like to know that too.

And yes, I could re-gear to get better towing power from a 5.4l, I could just buy a v10 truck and get rid of the expedition, etc. etc. etc. Those aren't suggestions I need, this is the specific idea I'm toying with right now.

Let me hear your wisdom!

There is a really really really good breakdown in the ford truck forums of a build where a dude did a 6.8 swap on his F-150. It’s like 700 posts long and mostly his step by step with pictures. Every about three or four pages he would say “DONT DO THIS, ITS NOT WORTH IT.” Had to literally piece things in from a Superduty donor truck and had a God awful time splicing wiring harnesses and tuning to make the f150 think it’s a superduty. Honestly, the motor swap itself wasn’t all that problematic, it was the electrical systems that made his life hell. YouTube has a few videos of his build. Looked and sounded dope as hell, but it was a tough job.

I was pretty set on doing it too until I saw that.

May be more time efficient and less expensive to get a good reman engine from a good reman company. Several of them include components that were an improvement on the 5.4’s biggest problems.

Wonder if a 6.2 would be an easier swap. Just. Thought

Yeah, as mentioned above, taking an engine from a different platform and generation and getting it to work properly is not for the faint of heart. Please don't take it the wrong way, but if you're asking these questions, it's probably a lot more work than you want to bite off. As in, you're looking at a lot more "unknown unknowns."

On top of that the minimal gains you'd get from an older v10 doesn't seem like it's worth the work, at all. I've contemplated a swap several times and the only thing that really makes sense (unless you WANT a huge project) is an updated 5.4L with cams and a tune. Check out this: https://www.expeditionforum.com/threads/5-4-engine-buildup-any-thoughts-on-upgrades-etc.50777/

Now that I've seen that massive thread I'm abandoning this 6.8 idea! Cool in concept, nightmare in implementation. No thanks. Going with a quality remanufactured engine and being happy with the ~10k tow capacity I have.

twodollars said:

Wonder if a 6.2 would be an easier swap. Just. Thought

Click to expand...

It might fit slightly better but you're still going to run into the same issues that you would with a v10 in terms of getting it to work in a different platform: wiring, harnesses, sensors, computers, etc. Again it would not be worth it for the relatively minimal gains, IMHO.

If I were to sign myself up for a huge engine swap job I'd go with a Cummins 12V or something like that instead.

What about a V-10 3V? That would be pretty close in age, and wiring might be easier?