[rxnodoze02]

Maybe? That is just what I heard about the plates I heard they are very specific to the cobra bc of the electronics. Maybe I’ll just go with the heads from the navi. What do you think. If I do go with the navi heads which ones. There are a set for sale but off a 4.6. Now are those no good bc they came from a 4.6 block and they were made for a diff deck height as well right. If so what do you think I should look for? thanks

 

[koessl]

You can use the Cobra heads still. From what I know... all V8 Modular heads are interchangeable between blocks. But the ports are different between the models. Which is why you would need a different intake. I personally would use the Navigator 4V heads/same Navigator intake. But thats because I dont want to spend a million dollars on a custom intake manifold.



WAIT! you can use the cobra heads, and intake but you would need these...

Reichard Racing

$375 for the adapter plates. They compensate for the added deck height (space between the heads as well).

 

[koessl]

That lifts the intake up an inch and brings the mounting points for the intake in a little bit so it fits the new dimensions... so unless you have an aftermarket cowl hood.. or want to cut a nice hole in your stocker, that may not work.

You may have to do that anyways because of the added deck height.

 

[rxnodoze02]

Ahh thats the ticket. Now I will just buy the 98 cobra heads and used those adapters so no big deal. The reason for this whole thing is my friend gave me a 5.4 engine and I want to do something with it but have been phased out of the modd motors. I have a 05 with a 4.6 and I have learned from building push rod motors unless you want to spend some coin making power. Go with a sc. To get the small blocks making 150rwhp extra you spend thousands anyway. For four big ones slap on the sc and call it a day atleast thats my take. Well to make a long story short now I never got into the internals of the modd motors. Thanks for all the help tho. By the way those plates are big bucks . Now I have to get a car to put it in. What about the whole engine managment. Can I just drop this engine in a 96 gt and then have it dynoed?

 

[koessl]

You can delete the plates.


You can also give me the motor... ill manage it, then you dont have to worry about it!

 

[zigbigadoru]

hah ^ nice. it depends on which route your going...if you go from 2v to 4v im not sure it will run properly if at all. if its 2v to 2v or 4v to 4v then it will run rough but you could limp it to a dyno or something.

 

[koessl]

I figured it was worth a try ya know?

 

[4sdvenom]

Ahh thats the ticket. Now I will just buy the 98 cobra heads and used those adapters so no big deal. The reason for this whole thing is my friend gave me a 5.4 engine and I want to do something with it but have been phased out of the modd motors. I have a 05 with a 4.6 and I have learned from building push rod motors unless you want to spend some coin making power. Go with a sc. To get the small blocks making 150rwhp extra you spend thousands anyway. For four big ones slap on the sc and call it a day atleast thats my take. Well to make a long story short now I never got into the internals of the modd motors. Thanks for all the help tho. By the way those plates are big bucks . Now I have to get a car to put it in. What about the whole engine managment. Can I just drop this engine in a 96 gt and then have it dynoed?

You can't use those plates for the 96-98 heads. They don't make them for B-heads. Those plates are to adapt a 99+ (C-head) intake to a 5.4 Navigator headed 5.4 motor. The Navigator heads have larger ports than any 4.6 4 valve head, so you have a few choices unless you want to degrade performance by mismatched ports or spend lots of money on custom stuff!
1) Use the Navigtor heads and use a Navigator intake (straight bolt-on).
2) Use the Navigator heads and use a 5.4 Sullivan intake (straight bolt-on).
3) Use the 99+ 4-valve C-heads and use a widened 99+ 4-valve C-head intake (straight bolt-on once intake is widened)
4) Use the 99+ 4-valve C-heads with an Aussie Boss 290 intake (Australian intake designed for c-heads on a 5.4, not impossible to get but pricey)
5) Use whatever heads you want and spend 3-5K having a custom intake made from scratch for it!
6) Save your money and buy a Shelby GT-500 crate motor with the blower all as one unit and benefit from the Ford GT heads it has.
7) Use Navigator heads and the linked adapter plates to run a 99+ 4.6 Cobra intake (unwidened).

Good luck, but it sounds like you have a bit more reserch to do before you buy. I don't mean that in a bad way, but even though some things are interchangeable doesn't mean there is the supporting componants available to make it work. i.e. yes 96-98 B-heads will bolt to a 5.4 block, but no there is no intake available or adapter plates available to make a 4.6 intake work with them!

Ken

 

[koessl]

ahhhh... glad someone else chimed in then!

 

[upstang]

WAIT your saying i can put four valve heads from a cobra onto my 2002 5.4 2 valve truck motor?

 

[4sdvenom]

WAIT your saying i can put four valve heads from a cobra onto my 2002 5.4 2 valve truck motor?

Yup, but you will have to change the timing cover, and locate the front accessories to the proper location for the year 5.4 4 valve timing cover you use. Then you will have to pick the intake choice thats appropriate for the heads you use from the options I listed a few posts above. You will have to verify that you can use your harness, but will most likely have to switch to a 5.4 four valve engine harness. (A cobra harness will work with modifications). You will definetly need a tune. Then there are all the little parts like fuel rails, fuel injectors, COPs, Primary timing chains, secondary timing chains, tensioner arms, tensioners, crank sprocket for timing chains, valve covers, COP covers, new coolant hoses, new thermostat parts (new location), etc. that you will need to source from a 4-v 5.4. I'll tell you from experience. I was doing this swap in my Cobra and it was much easier to start with a 4v 5.4 Navigator motor that I purchased from a salvage yard in running condition for $1400 than to think about piecing all the stuff together to get it right.

Ken

 

[rxnodoze02]

haha. Your prob right I should give it to you so you could burn a hole in your pocket instead. Because im sure you know thats whats gonna happen Thanks for all the help I def have a much better understanding of how to go about this. They do make adapter plates so the 4.6 can work on the 5.4 the link is up top. Reichard racing check it out

 

[4sdvenom]

haha. Your prob right I should give it to you so you could burn a hole in your pocket instead. Because im sure you know thats whats gonna happen Thanks for all the help I def have a much better understanding of how to go about this. They do make adapter plates so the 4.6 can work on the 5.4 the link is up top. Reichard racing check it out

I know exactly what it takes to do this swap, and I definetly won't be burning a hole in my pocket to do it. Thats why I scrapped it and decided to do a 5.3 build with the Boss 5.0 block and a stroker kit. I know about those plates, but they only work for a 99+ intake on a Navigator headed 5.4 as I posted above!

Good luck with the build!
Ken

 

[upstang]

how much more horsepower can the 4v 5.4 make over the 2v 5.4