5.4L swap help

Dec 16, 2019
19
1
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Alberta
So I’ve been doing a bunch of looking around at the idea of swapping my engine. I’ve got a 96 Gt with around 300k km on it. Engine could use a refresh and after reading how straightforward a 5.4 swap can be I’m interested. I just have a few questions.

So the 5.4L 2V SOHC is the one knownfor being easy if I am correct. That’s found in F series trucks and other things.
I’ve come across all sorts of people doing the 4V DOHC out of the navi alternatively and netting more torque and some power, plus there are adapters to run the coyote or boss intake. From what I’ve read this is quite a bit more difficult AND expensive.
Is there a way to put 4V heads on a 2V block? Or is that just wasting my time. Bottom line is a want to do SOMETHING to the engine and figured I’m better off swapping in a 5.4 (even if it’s not MAJOR HP gains) it would still be better to build that engine up over a tired 4.6.
Thoughts anyone? Are there options for a 5.4 2V intake other than adapter plates to run a 4.6 intake?
 
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tsemmett

Active Member
Jul 2, 2019
259
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38
38
US
I'm in the same boat, 192K miles (307k km) on an NPI engine in my 98.

From what I've gathered, the 5.4 really isn't a huge advantage over the 4.6, and that has a lot to do with a lack of intakes for it. It'll make more torque, but it also won't rev quite as high (with that long stroke). I think for what you're talking about doing, you might be better off with a PI or 4V 4.6, especially an aluminum block one. For example, an 03-04 Explorer 4.6 would shave 80lbs or so off your front end and give you another ~40hp in stock trim, while opening up other intake options (including positive displacement superchargers). An Aviator 4.6 4V would still probably shave 50-60 lbs and gain ~80hp in stock form.

Swapping 4V heads to a 2V is possible, but you will drop compression, and it does require a fair bit of part swapping (timing cover/timing set for sure).

That said, Navi 5.4s are pretty cheap to find, so if eating up work space in your engine bay and hammering headers to fit seems reasonable to you, it's a strong contender. I was leaning this way, but after reading how tight things sit, I'm pulling back to a 4.6 and rethinking the idea of boost.
 
Dec 16, 2019
19
1
13
18
Alberta
I'm in the same boat, 192K miles (307k km) on an NPI engine in my 98.

From what I've gathered, the 5.4 really isn't a huge advantage over the 4.6, and that has a lot to do with a lack of intakes for it. It'll make more torque, but it also won't rev quite as high (with that long stroke). I think for what you're talking about doing, you might be better off with a PI or 4V 4.6, especially an aluminum block one. For example, an 03-04 Explorer 4.6 would shave 80lbs or so off your front end and give you another ~40hp in stock trim, while opening up other intake options (including positive displacement superchargers). An Aviator 4.6 4V would still probably shave 50-60 lbs and gain ~80hp in stock form.

Swapping 4V heads to a 2V is possible, but you will drop compression, and it does require a fair bit of part swapping (timing cover/timing set for sure).

That said, Navi 5.4s are pretty cheap to find, so if eating up work space in your engine bay and hammering headers to fit seems reasonable to you, it's a strong contender. I was leaning this way, but after reading how tight things sit, I'm pulling back to a 4.6 and rethinking the idea of boost.

great info thanks. After weighing my options and budget I’m leaning more towards rebuilding my current 4.6 and putting a bigger cam along with a PI swap. Down the road Once I have a more realistic budget I’m thinking Forced Induction as well. On3 turbo or Kenne bell blower is my plan. I’m still in high school so 4-6k On forced induction and other upgrades is a little out of consideration lol. Maybe someday I’ll do a swap just to say I did.
 

tsemmett

Active Member
Jul 2, 2019
259
37
38
38
US
Yeah, I probably wouldn't get too wild in high school; I made the mistake of buying a project car right out of high school (a 35th Anniversary Supercharged T-Bird). It ended up getting scrapped after sitting for so long it rusted to hell. There are more important uses for money at that age. Now I'm twice as old and have a lot more money to do stupid stuff with, and I just can't bring myself to buy new (I don't like the new Mustangs anyway). So, rebuilding/upgrading is the most likely direction.

You might find a full PI swap (w/ Cams) will be fine for a while, and people have certainly made very respectable power numbers with power adders and stock heads/cams. If anything, I'd probably put a little in suspension or gears before I would a hotter cam; they'll make a bigger difference in drive-ability.
 
Dec 16, 2019
19
1
13
18
Alberta
Yeah, I probably wouldn't get too wild in high school; I made the mistake of buying a project car right out of high school (a 35th Anniversary Supercharged T-Bird). It ended up getting scrapped after sitting for so long it rusted to hell. There are more important uses for money at that age. Now I'm twice as old and have a lot more money to do stupid stuff with, and I just can't bring myself to buy new (I don't like the new Mustangs anyway). So, rebuilding/upgrading is the most likely direction.

You might find a full PI swap (w/ Cams) will be fine for a while, and people have certainly made very respectable power numbers with power adders and stock heads/cams. If anything, I'd probably put a little in suspension or gears before I would a hotter cam; they'll make a bigger difference in drive-ability.
Yeah gears were in my plan as well, forgot to mention it. Probably 3.73 but I might even go 4.10s as the car is only used to rip around town, not commuting or major highway driving. I have lowering springs but I’m thinking of going coil overs instead. 250whp would be perfectly acceptable for me and I’m guessing that’s probably what I’ll make with that I’m doing. I might send it for some long tubes as my stock headers have some bolt issues. Regardless I’m learning a lot from the car and can’t wait to keep doing some more stuff