[K7cobra]

hay guys im planing on trading my cobra well more like thinking about it. befor i say ok to a trade i was wondering if there were any 5.4 swap rightups. because if i keep this car i want to do a 5.4 with 4v heads off my cobra

[majorownage]

Originally Posted by K7cobra hay guys im planing on trading my cobra well more like thinking about it. befor i say ok to a trade i was wondering if there were any 5.4 swap rightups. because if i keep this car i want to do a 5.4 with 4v heads off my cobra

Start with a navi engine. The have a forged crank and the same heads. Your cobra cams will swap in directly. The cheapest route for a good intake would be to use your cobra intake with spacers to fit the 5.4. Remember that the only good 5.4 block is the ford gt aluminum; the navi aluminum blocks are wap, good for a 700-800ish hp.

[Mach Boy]

The 5.4 will fit under your hood. You can't use your intake (unless you buy adapters) and you can't buy a longtube header unless it is custom. You're probably only going to see a little bit of a HP gain over the 4.6 but you'll get a nice torque increase. The best way to go is to buy a Sullivan intake or have an intake made custom.

[K7cobra]

thinking of making a intake and headers my self if i do swap

[DickH]

Originally Posted by majorownage Start with a navi engine. The have a forged crank and the same heads. Your cobra cams will swap in directly. The cheapest route for a good intake would be to use your cobra intake with spacers to fit the 5.4. Remember that the only good 5.4 block is the ford gt aluminum; the navi aluminum blocks are wap, good for a 700-800ish hp.

Heads are not the same, they are their own category similar to C heads, but with a larger intake port. He cant use his cobra manifold, adapters just cover the width difference, they dont convert B to C, so he would need to get his hands on a C head intake if he wanted to use the adapters. Next easiest option would be to get a sullivan manifold, if he watches for one a boss290 intake is even better. And as far as I know the only aluminum 5.4 is whats found in the ford GT, everything else is cast iron, and many people have gone a fair chunk past 1000hp, so its plenty strong enough.

[K7cobra]

Originally Posted by DickH Heads are not the same, they are their own category similar to C heads, but with a larger intake port. He cant use his cobra manifold, adapters just cover the width difference, they dont convert B to C, so he would need to get his hands on a C head intake if he wanted to use the adapters. Next easiest option would be to get a sullivan manifold, if he watches for one a boss290 intake is even better. And as far as I know the only aluminum 5.4 is whats found in the ford GT, everything else is cast iron, and many people have gone a fair chunk past 1000hp, so its plenty strong enough.

thanks for the info my question is would a saleen or roush intake work for n/a

[DickH]

not familiar with a NA 5.4 saleen or roush intake so I dont know. You would need to either get a 5.4 dohc manifold, or use adapters. Adapters and a cobra manifold are a cheap option that will work. Or you can hop over to corral.net and talk to birdman491, he sells 5.4 dohc kits that include an intake and everything fits under the stock hood.

[K7cobra]

im not that good with the 5.4 will any intake used of a 5.4 fit any 5.4 engine like could i use a f250 intake on the navi 5.4 motor

[DickH]

one of the hardest parts of a 5.4 swap is the manifold. You can get a sullivan manifold for the 5.4. They discontinued it will be harder to find new, even used it might not be easy to find. Even harder to find would be to get a boss290/boss260 manifold, made in australia for 5.4 dohc motors in cars they get that we dont. The cheapest option would be to get a proper set of adapter plates that make a 4.6 manifold fit.

[Mach Boy]

Originally Posted by DickH one of the hardest parts of a 5.4 swap is the manifold. You can get a sullivan manifold for the 5.4. They discontinued it will be harder to find new, even used it might not be easy to find. Even harder to find would be to get a boss290/boss260 manifold, made in australia for 5.4 dohc motors in cars they get that we dont. The cheapest option would be to get a proper set of adapter plates that make a 4.6 manifold fit.

+1 and the intake is the most costly part of the swap if you don't go the adapter plate route. I know Birdman's setup was going for more than 2000 last I talked to him, but he knows his stuff. He used to work at Ford as an engineer I believe.

[DickH]

im not sure what all comes with the kit, but 2500 or so for everything you need to make a 5.4 a direct swap isnt too bad.

[K7cobra]

no its not a bad price for the swap. i did do some rechearch on the adaper plates for the motor i might just have to go with a 2v or a 3v swap in stead of the 4v and on the other note i dont think it would be very hard to build a custom intake or do some heavy modding to the stock intake depending on what it looks like. and dose any one have a picture of the 5.4 in the navi

[Mach Boy]

I'd rather have a 4.6 4V than a 5.4 2V.

[DickH]

Yeah if you are going to swap in a 5.4, go 4v. The intake part isnt easy, just join multiple forums and watch the classifieds. The stock navi intake is way way too big to work with, it wont come close to fitting under the hood.

[Blk01ponyGT]

why not just keep the 4.6? jw.. 5.4 seems like a lot of hastle when you can pull great power out of a 4.6. but hey if you do do it props to you!

[K7cobra]

i would keep the 4.6 if it dident caust a arm and a leg to build

[DickH]

A stock navigator with the swap kit from birdman makes decent power, with a chunk more tq than you are likely to get out of any combo using a 4.6.


If you swapped over your 98 cobra intake cams and degreed it properly, it would probably make a solid 25hp+ more.

[K7cobra]

+1 thanks for the info its starting to suck im havin a hard time finding a 5.4 4v

[DickH]

Just look around for navigator motors, the 5.4 4v should be found in navigators from 99-04, and can be had for 1000-2500. Car-Part.com--Used Auto Parts Market is a great place to start, it searches through places that part out cars, and you should be able to find a motor thats not too far away.

[K7cobra]

i found a few really close to me what do you think about stacks on the 5.4 i think it would look sick and more like a race car but thats just me how hard would it be to make stacks