[rxnodoze02]

I have a 2000 5.4 2v from a truck. Can i use the 4v heads from a nav or shelby on this motor. What else do i need to change if i change the heads timming cover etc. Thanks chris

[zigbigadoru]

yes you can grab some 4v heads. dunno bout the other stuff though as im not too edumacated in the 4v area.

btw i would grab a set of shelby heads if you have the choice between shelby and navi. navi is the low man on the totem pole as far as 4valve heads go.

[rxnodoze02]

i know but shelby heads will be a few bucks more. I could prob find a set of nav heads much cheaper. Are the cams the only diff in the heads or are they ported diff to. Yeah I really want to know if there is anything else. let me know if you learn more thanks

[SWEET2KSTANG]

the ports are different as well if i remember right. you will have to get the adapter plate for them. the navi heads are good heads and more beneficial on a 5.4 application over a regular c-head. you will have to run a navi intake, ustom intake, or a sullivan piece.

[rxnodoze02]

I found 4.6 96 cobra heads and a set of 96-98 4.6 mark 8 navi heads will these work on a 2000 5.4 block? If so which heads would you go with. thanks chris

[SWEET2KSTANG]

the modular heads will interchange on amy modular block. as for the heads. you say 96-98 cobra heads, and set of 96-98 mark 8 navi heads? uh the 4v heads up to 98 were all b-heads, the 99+ were c-heads. if you run a b-head on a 5.4, you will have to have the intake widened for it as well.

[LGHTNG02GT]

b heads are ok for boost or a high rpm race motor...personally i would look for a good set of C heads from a 99/01 cobra or a mach or an 03/04 cobra

[rxnodoze02]

yeah there was a post comparing all the heads saying that the best heads were 00R heads. I like the idea of the 96 heads tho. They stated that the intake was a full 55cc larger than all of the other heads. While this kills low to mid range power but really helps in high rpm and really shines in the case of a supercharger. I think that is going to be the road I want to walk down tho.Plus the 03 cobra, Aviator etc heads go for a lot more money I dont want to be cheap but its a big diff. If i could find them at a good price i would pick them up right away. Let me know what you think thanks

[SWEET2KSTANG]

the 5.4 will benefit from all the extra air it can get. you will save going with the b-heads, but will tie up some money to have a cobra manifold modified to fit the 5.4 as well. persoanly, i would do a set of navi heads, and a sullivan intake as well depending on what kind of set up you go with.

[rxnodoze02]

Which one are we speaking about Exhaust mainifolds or intake mainfolds. Im assuming the intake. If so I would use the 96 cobra heads and the intake on the 5.4 block. 96 heads heads would love the volume of the 5.4. Plus Cant I use the IMRC plates to solve the low end part a little. Then you could port the exhaust bc that were those heads fall short. What do you think Thanks

[SWEET2KSTANG]

to my knowledge, the pre 99 navi's were all 2v's. i am not sure if there were any 4v 5.4's made that were b-head 4v's. even if so, the runners will be long and choked so doing the swap wouldnt benefit. you will have to have a cobra intake modified to fit.

[rxnodoze02]

The heads would be from a 96-98 cobra and I would put them on the 5.4 block and then go with the cobra intake. What direction would you go with electrical . Would a 96-98 wiring harness be a good start

[4sdvenom]

Originally Posted by rxnodoze02 The heads would be from a 96-98 cobra and I would put them on the 5.4 block and then go with the cobra intake. What direction would you go with electrical . Would a 96-98 wiring harness be a good start

Just remember you will have to have the Cobra intake cut in half and widened to fit the 5.4 if you use the 96-98 Cobra heads. Its not just a bolt on affair. However, if you use the Navigator heads, you can use either a Navigator intake or a Sullivan intake, both which will require no modifications to bolt on, but will vary greatly in performance from each other depending on your goals.

Ken

[rxnodoze02]

I dont understand if you have 96 cobra heads why cant you buy a 96 cobra intake to match and bolt right on? Deck hight ? bc of the 5.4

[03_StangGuy]

Originally Posted by rxnodoze02 I dont understand if you have 96 cobra heads why cant you buy a 96 cobra intake to match and bolt right on? Deck hight ? bc of the 5.4

I believe the deck height it taller so the spacing between the intake ports is larger.

[koessl]

Think of it like this...


This is a 4.6 - "v"
Here is a 5.4 - "V"

Look at the space between the two highest points of the "V"s... The 5.4 is wider. Hence the 4.6 intake wont bolt on to the 5.4 Block/head combo. You can use a 5.4 intake (Navi) though. But from what I hear... it doesnt offer the performance that the 4.6 (Cobra) intake will.

[rxnodoze02]

ok so it is the deck height. There is no other intake that will bolt right on? Does anyone have a pic of the 96-98 cobra inake modded. thanks

[koessl]

google has hella pics.

98 cobra intake manifold - Google Search

[rxnodoze02]

Cool thanks what about the IMRC plates im I gonna have a problem finding them for the 96-98 cobra. I read a post before and they were saying how hard it is to find them for the cobra bc its electronic not air actuated like the ones for the navi heads.

[koessl]

Cant you get one from a Lincoln Mark VIII (Essencially a 96-98 Cobra motor)? I hear of people deleting theirs every so often? Just keep an eye out... The threads show up here occasionally.