EFI or no?

EFI is nice when its all tuned perfectly and the bugs ironed out, but its hell until then. With a 408, you're going to need dyno time and probably some kind of chip burned for the ECU. Another option is to get a twEECer and prog it yourself or find someone who can. For a healthy 408, you'll probably need at least 30lb injectors, maybe even 36 or 42. Look for the stuff from a mass-air Mustang and an A9L computer.

I will gladly post my stupid is as stupid does vote on this topic. I have had a Holley Pro-jection 670 cfm throttle body setup for over 10 years. Of course, as I am sure you are aware, this is little more than a two barrel carb with a dumb-a**, by today's standards, computer actuating the 2 injectors, thereby controlling the flow of fuel, choke, accelerator pump, etc. Regardless, I haven't had to screw with the thing at all (other than twist on the little controls on the CPU for sharts and giggles) in all that time, and I have been amazed by its efficiency for such a rudimentary setup. Hands down, in my opinion, it beats the crap out of the Autolite and Holley 4 barrel carbs I've tried on the same engine and had to constantly screw with.
I have also driven Fox body cars w/ serious cams that would purr like a kitten putting around but that would scream like a banshee when opened up and quickly hit 6,500 rpm's. I know there are a good deal of old school carburetor guys on this forum, and more power to them. I believe they are absolutely correct when they say a properly tuned carb will deliver the same performance, if not slightly better, on the dragstrip, but in IMHO, carbs don't compare w/ F.I. in terms of driveability w/ wild combos.
I will admit freely that I don't know the best intake components, etc. on the market today. A few years ago, when I was really into this topic, I would have had no qualms recommending the GT-40 tubular upper. Today, I'm sure that information would be dated, especially in the advent of stroker buildups. My suggestion would be to pick up a 5.0 or late model mag at your local newsstand and check the resources on the 5.0 forum of Stangnet.

P.S. My commment regarding Fox body cars certainly had a good deal to do w/ the roller cam engines in those vehicles, at least from 1986 1/2 onward, which are the cars that I've driven. I refuse to let myself get hung out to dry for the flames I will receive for that comment w/out at least some qualification. Let the burning flesh begin!!!!!

Driveability is the key word here, EFI can tame some of the wildest motors. Carbs no doubt can make equal power, but no way can it match the constantly varying timing and fuel curves that EFI provides. Although to get max power you may need a dyno tune,you dont NEED one to have good running street car. Ive got a buddy with a sweet running 427 stroker, runs a stock A9P processor 36 lb injectors ,matching air meter on an otherwise stock control system. For a 408 a holley systemax intake would work good, so would a vic jr, or even a performer RPM. A GT40, cobra or explorer intake would probably choke the power on the top end but make killer torque down low. stock fuel rails will be fine, but you'll need a higher output pump than a stock ford pump. You can source most of the parts from any mass air car, but the 89-93 mass air mustangs are the donor car of choice.

I think the spyder intake from pro-idustries/coast high performance (I think) would be a cool intake to try. One thing to worry about with a 351 based motor is hood clearance with the efi intakes and this intake seems a little bit "shorter". I couldn't get my track heat to fit with the 1" spacer so I had to throw the spacer out. I think a 351 is an inch taller than a 302? Could be wrong. Also, my car is a cougar so clearance may or may not be different.

Well…my personal opinion pretty much matches the posters above. Drivability is key here. If you drive your car for any significant amount of time you will love the EFI. A carb just cannot beat the “hands off” abilities of the EFI system. A carb can make just as much power as EFI but the EFI system will be able to cope with the wilder setups and not break a sweat.

Now here is where I personally stray from the above posters. I would not use any electronics or harness from any donor car. I would grab a harness to harvest connectors for injectors and sensors but that is it. I am using a Megasquirt system and I am totally happy. It is much easier to build your own harness rather than trying to cleanup and adapt the factory harness to your vehicle.

I like the Megasquirt system for several reasons:

It is totally controllable.
The system is open source. If there is something that you do not like about the system…grab the source code and change it.
You build the hardware and thus understand it fully.
No Mass air meter restrictions in your intake.
It is a proven system that is very reliable.
The engine harness is MUCH simpler than a factory ford harness.
It is a system that is meant to be universal and can be adapted to many components.
It directly supports EDIS so you can ditch the dizzy if you wish and it supports the TFI distributor it you don’t.
If you change your system (like add a supercharger) just hook your car up to a laptop and retune it. No expensive chips or tuning software.


I am not putting down the EEC-IV computer it is an excellent setup but the tuneability of Megasquirt and price points just makes sense for me to run the MS system.

www.megasquirt.info
www.msefi.com


Hope that helps,

Rufus

Skywalker, I am converting my mild 302 to EFI as we speak. Although my post count is low, I have been building Mustangs for 10 years and went to start posting again and my user name and password weren't accepted. I am gathering parts now and the conversion will begin shortly. I plan on posting lots of pics! I say EFI for a non original street/track car.