408 EFI Build

[jsniper06]

Ok guys, I have a question about my best option. I have a 408 stroker, carbed with stock heads. I want to go EFI. Just purchased Lightning Gt40 lower with 30 LB injectors and a Cobra upper. I also own a set of gt40P heads that I may use ( but not 100% on that ). I would like to to get around 370 to 400 HP out of my setup. Is this doable? Where should I go from here? I know I need harness and computer. Should I use these heads or get new ones? Any info from the EFI gods would be great, I have never delt with EFI before. Thanks

 

[KyleQ]

If you can't get 400HP from that you fail. You basically need a Mustang harness, ECU and a tune - your 408 WILL run with the factory 302 computer, just don't expect it to be a powerhouse.

GT40 heads on a 408 isn't what I would call an ideal setup, you need at least a 185 series head, if not a 195/200 to properly breath over 3500RPM. Those intakes are great for low end torque, they will produce a maximum of 450HP before porting - I'm running the same thing.

 

[bmc69]

Probably won't get there (400 HP) with those heads..as noted..unless you are talking about some pretty high RPM. Is it HP you are after?..or torque?..and at what RPM range?

My 408 only puts out about a peak of 340HP with 190CC heads, 2.07 intake/1.65exhaust valves.

 

[bronco-billy-66]

My 408 only puts out about a peak of 340HP with 190CC heads, 2.07 intake/1.65exhaust valves.

How much torque at what rpm??

 

[408Bronco]

I would upgrade to some better flowing heads, i'll be running the TFS 206R heads, the stock heads were designed for the 351 CI, adding another 50 CI will demand for more flow from your heads.

 

[bmc69]

How much torque at what rpm??

Mine? From the engine dyno..496 ft-lbs at 2900 RPM. ( I so wanted to bust 500..)

"All in" at less than 4000 though...hence the low peak HP numbers.

 

[mattt]

Are you shooting for 400 at the flywheel or the wheel? I don't know that an iron GT40 will flow adequately for a 408 with those expectations.

 

[rjrobin2002]

Mine? From the engine dyno..496 ft-lbs at 2900 RPM. ( I so wanted to bust 500..)

"All in" at less than 4000 though...hence the low peak HP numbers.

Who needs a diesel with those numbers?

 

[bmc69]

Who needs a diesel with those numbers?

That was exactly the goal..

I've since regretted it though. Phenomenal breakage over the last 8 years since I started wheeling it. Not any problem with the engine though..%)

 

[jsniper06]

I am shooting for 400HP, but if I dont make it I can live with it. So I guess I need some heads. Does any know of good heads under a grand. Whats the best place to get a computer and harness?

 

[Bronchole]

Does any know of good heads under a grand.

And it starts..... It's not just the heads. Its also all the other crap that comes with the heads. For instance I got my TFS heads for $1200. But then I had to change over to non-factory roller rockers because the heads are not compatable with the factory roller rockers. That also got me to have to buy a new set of valve covers because the aftermarket roller rockers are not compatable with the factory valve covers..... You see how it goes. I refer to this as the project snowball effect. Grab your wallet, its gonna hurt!

Dan

 

[av bronco]

No problem with a 408, Im running a 427 stroker with ford efi, got a moates quarterhorse to tie it all toqether.

 

[mattt]

One option that wont break the bank are Ford Motorsports aluminum heads. Yes, they're not the best out of the box vs. a Trick Flow or other aftermarket head, but they are still better than iron heads. Since they are not considered the cat's @$$, they generally sell for a little less than other aftermarket aluminum heads. As far as I know, stock rockers and hardware will work with the Ford Motorsport heads.

 

[firehawk]

One more thing to think about it what headers you have, sounds like you might not be using the P heads but they have issues with headers fitting.

 

[jsniper06]

No problem with a 408, Im running a 427 stroker with ford efi, got a moates quarterhorse to tie it all toqether.

Thanks I will check them out. PM you if I have any questions

 

[jsniper06]

One more thing to think about it what headers you have, sounds like you might not be using the P heads but they have issues with headers fitting.

I think the p heads are out. I kinda knew that from the start, just needed a little push to get new ones. But I am running BCB shortiers

 

[jsniper06]

Does anyone know what size throtle body came on the 93 cobra upper? 60,65,70?
What size do I need?

 

[bronco-billy-66]

..496 ft-lbs at 2900 RPM. .

 

[KyleQ]

I would suggest looking on your local Mustang boards for parts - you can easily get used heads for around a grand. My Trick Flows we fully rebuilt, decked and had the castings cleaned up (nearly ported) and I paid $900 - deals can be found.

I've also proven that factory Ford EFI valve covers will clear the intakes you are running and the 1.6RR's I've got on my heads - .565 lift cam.

I would go with a 70MM TB - you will have to hog out the intake, but not too much. You should also get a MAF to match it, look at Pro-M for the MAF and AccuFab for the TB.

 

[bmc69]

You should see the shelves in my office that are a display area for 'pieces' left over from various driveline carnage.%)

On the positive side...I seldom have to shift gears.

I won't build another one like the one I got now.