last tech(almost) on 3v swap... the hood


Active Member
Jul 17, 2005
huntsville, AL
if you guys remember i told you the stock hood doesn't fit. after buying a cobra "RR" hood, and wasting alot if time fooling with it.

i only needed to remove the liner and cut a small section of bracing and it fits. so i was wrong. i never tried to fit it because it looked like i needed and inch or so. that's what i get for thinking. so anyway, for those willing to give it a go, the stock hood fits fine. no need for aftermarket hood. i'm still going to go all the way with this, so the other hood will be necessary later.
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i spent about 5200, but maybe a thousand is trial and error parts that didn't work. i'm including all of the parts required to get it running. if labor was included it's a crapload more. although if i did it again i could do it for 3500 or so. the motor costs 2900.00. you could find it soon at bone yards for less i'm sure. i'm planning to run it at the track this sunday, or as soon as the DR's get here.

i spent 200.00 for 4.6 3v manifolds that don't work for example. 350.00 for frpp headers that i ended up cutting to the flanges in the end and re making them. there is a new header that looks like it avoids the steering shaft problem altogether. i can't think of the brand, but for someone else that can't build a header, that looks like a good option. basically there isn't room to run more than one tube above the ports, so they have to run under . perfect equal length takes a small hit to get long tubes in. shortening the tube 1" at the port to bring them closer to the block will let most 4.6 headers work. the flanges need to be plasma cut. so i spent $350 + $200 plus stainless tubing just for headers. if you don't care about power as much , adapter plates and porting your stock 4.6 manifolds will work. an adapter plate is simply a flange that works with 3v and screws into the heads with studs to bolt your manifolds to.

as far as time...

if you get all of the parts ahead of time, it bolts in. and your PCM and fuel system works. there is a small mod needed for firing the fuel injection. you use your oil pan and pick up. the oil pump for 3v is like huge volume. so i made a paper gasket and removed the 4.6 pick up O-ring. the baffles on the front of a 4.6 oil pan hit the crank so bend them just enough to clear it. etc. etc etc.mount and every thing else work.

the 5.4 3v is rated as a pick-up truck , so anything you do to improve it over truck exhaust, intake, pullies wake it up. of course i'm going to post the tickets after track day. so either the torque has masked it's low power, or this has a hell of a lot of power. good ET and low MPH means low hp. i just bought the latest BFG DR's they have a slick middle. maybe 255's are enough to get an idea. later. there a full write up on this that you did somewhere, with some pics and whatnot? If so, I missed it and I for sure want to see it. If not...what are you waiting for! I would love to see a full write up with some pics...let us know how it does at the strip...
wow thats alot of work/money billfisher, good luck with that project it looks like its gonna work out alright. although 3500 doesnt sound bad its more then i got right now, and lets be honest, i more then likely am not gonna be able to do the labor so i would have to pay some shop.
Great job Bill! It looks like im also going the 5.4 route down the line, so ill be in touch with you. Ill be doing the Ford GT 4V heads though, do you thing these things will fit in a stang? I dont know how the 3Vs compare in size.
the 4v heads are a little wider. the issues that get people from doing it are the intake and driver's side valve cover. the navi manifold is useless. i have been told the valve cover can be grafted from a combination of the navi and 03-04 cobra. even if it requires custom work it is worth it. cams are another issue that holds people back. the navi are too small for big power. more $$$. and navi's 4v are going to get rare.

boss330 is at the 700fwhp range right now, but Ed olin reached 490 fwhp without the benefit if a real intake or big cams, longtubes with 3v. supercharged 5.4 3v's on are reaching the 440rw range with tune , exhaust, blower. that's considerably better than lightning. the 3v is going to out torque 4v.

i guess that's why i tried it. if Ed had said it was impossible to get power, and he was NOT a ford engineer the Mach1 would be in my car now.

i fully believe i have added 15 lb-ft to the motor with bolt-ons. i am totally excited to see the 60' times. i worked my ass off in november out in the cold and rain.(i have no garage) to make the last week of track time. so i've been waiting for months.
Hmm I assume the navi heads are simular in size....but the heads I will buy are Ford GT heads, I believe they flow in excess of 300CFM in cast form. Thanks for the info. Im aiming for 500+ RWHP N/A...and thats pretty much in the bag.
wow that is alot more work then im willing to do. guess thats why im just going to slap on a blower. that is awsome though and i wish good luck with it. you too hotmustang, 500 rwhp na is just plain sick, but way too much fabrication for me.

if i had more know how maybe id think about doing somthing like that. however i like to keep things sort of stock without heavy modification so if need be (and i hope not) ford would still know what the hell they were looking at to an extent.

the most fabrication i am considering is an aluminum built block. i like things that just bolt up easily.

good luck though at the track. cant wait to see some times.