All original 66 with a 300/4speed. Want to convert to EFI / Aod utilizing the original engine. What do I need and need to modify/ Help please. This will be my build thread.

 

Your best bet is get a complete 1996 F150/250. Preferably one that runs, the 96 is the last year Ford produced the 300 I6, it is a OBDII system that has mass air flow and split exhaust. If you were to find an F250 you could probably even use the stiffer springs from it.

I will sell you my F150 96 AOD 2wd next spring, it has only 119K miles on it. It is rusted pretty bad but I still drive it everyday. As of right now I would not have any issues taking it on a cross country cruze and expecting to get home without any breakdowns.

On the other hand...................

Sell me your 66 and I will do the job!!!!! LOL.

 

You can't properly convert the original engine to EFI. Sure, you can get it to run, but it won't perform well. And for the trouble involved you'd be better off with a complete engine assembly from a junkyard 95 or 96- you can get one for less than $400 (as little as $150 if you shop around). And if you're a stock/ original purist like me, keep the old engine in your garage so you "could" put it back someday.

Your carb motor has very different heads from what the EEC is designed to think it's controlling. First, the CR is different. The computer will not properly calculate knock and rich/ lean mixture.

Second, EFI is designed to run with air injection directly into the head through an air rail over the valves (carb heads do not have the ports for this). If you put the air somewhere else (or not at all), this will mess with the back pressure at certain moments, again screwing with the EEC.

I would know this because I have a 91 with a '79 engine installed by the PO. Trust me, you don't want to do it.

You could simply replace the head with an EFI one, but at that point it's no longer original. Go the JY route.

 

I will disagree with this, and no offense to you, but back pressure isn't needed for a 4-cycle motor to run correctly. What is needed is exhaust flow. Too big a diameter of exhaust, it can't flow at low rpm. To small, it can't flow at high rpm. Too big of an exhaust takes away low rpm torque. Too small of an exhaust takes away high-end horsepower and chokes the motor.

Those air rail ports in the head are situated over the exhaust ports on your EFI head. The AIR rail is part of the Air Injection Reactor pump, or smog pump. It blows clean air directly into the exhaust stream as the piston pushes it out of the chamber and through the exhaust port into the exhaust manifold.

The idea is so that it allows the unburnt gases to finish their combustion cycle or get close to it before it reaches the oxygen sensor and catalytic converter, where the computer then decides how to best adjust the Air-to-fuel ratio to reduce emissions.

Having a smog rail or not alone won't make the motor run improperly if it was fuel injected. The only way it could is if it threw a code. If it didn't throw a code, the computer would merely adjust the AFR to get the desired fuel mixture. The smog pump and AIR system also has no power-robbing drawbacks like, say, an EGR.

What is definitely needed though is an EFI head for that EFI system. Like a previous poster mentioned, you need a higher compression ratio, the chambers in the EFI head (which is known itself as a fast-burn head because of the chamber design), and the associated fuel injection stuff like the computer, intake, throttle body, bracketry, etc.

To the Original Poster (OP), have you considered the Holley Avenger TBI system? I'm a die hard carburetor guy, but I will admit, I've looked at it myself. It's tuneable for mileage, performance, and anything in between. You hook up an electric, high pressure fuel pump, oxygen sensor, mount the computer, mount the fuel injectors and throttle body to a 4-barrel intake manifold (Offenhauser C-series would work well) then crank the vehicle and program it. The computer reads it and calibrates the settings as you drive. The best part about it is the only thing needed to make it work is a 4-bbl intake. It doesn't matter what motor it goes on or what head, cam, etc. you have. You set the engine displacement and other things on the tuner, then select what you want the computer to tune it to and it does the rest. It's also a stand alone system, which means you don't have to have anything other than a motor and a 12 volt power source. I recommend going to their website to have a look. It's most popular for the application your working on, a 1966 EFI 300.

Just throwing it out there, and no, I don't do marketing. LOL.