This is a compilation of the experiences and advice of several people who have converted their carburetted trucks to EFI and is directed primarily at a mass air flow (MAF) conversion as the speed density (SD) setups are more difficult – often requiring reprogramming of the EEC.

The GT40 351W lower and Cobra (GT40) upper is a good combo for a 351W and sufficient for over 300 hp. The '95 Mustang Cobra R (351W) used an 80 mm Lincoln Mark VIII MAF and 24# per hour injectors. These injectors will easily support 350 HP and the 80mm MAF is a better choice than the 70mm, as you get to use more of its linear range, making fueling more accurate.

The reason there hasn't been a MAF conversion for the Lightning is because it has an E4OD transmission, and there was no ECU that was both MAF and that would control the E4OD. That’s changed now, as there are several truck EECs that are MAF and work with the E4OD, for example the 5.8L F5TF-12A650-BYA, the 5.0L F5TF-12A650-HB and the F5TF-12A650-GB.

The SVO conversion for the Mustang contains a processor, harness, MAF, and a block that fits between the harness and the processor with the MAF wiring leading from it. SVO (Special Vehicle Operations) is a division of Ford MotorSport Performance Equipment, 44050 N. Groesbeck Hwy, Clinton Township, Michigan 48036. Their technical assistance hotline phone number is 313-337-1356 (I think this is wrong – it comes from their 1996 catalog).

There are some kits available that are just a few wires and a MAF but they often require you to buy a processor and there are reports of idle problems with them. There's supposed to be a wire (on Mustangs), that’s not in these cheap kits, for the fuel pump that has to be jumped to the relay under the driver's seat. Without it a code is supposed to get set and it may be the reason for the idle problem. My car had no such stringing of wires and, so far as I know, there were no codes set (never checked). It’s unclear whether SVO did anything to alleviate this problem but, if they did, it was likely in the plug that goes between the harness and EEC, which the cheap kits don't have.

For information on a kit to convert vehicles with E4OD transmissions to MAF, call Best Products / ProFlo at 1-800-399-9223 and ask for Jim.

Specifications for Coby’s setup:

• 1973 Bronco (4WD)
• 4400# GVW
• 6.5" lift
• 33x12.50 tires
• 4.88:1 differential ratio
• C4 transmission, heavily beefed up
• 351W engine bored and stroked (’69 block).
• .040 over bore
• 423 CID / 7.01 L
• 10.5:1 CR
• eagle 6.250 rods (Chrysler dimensions; narrowed)
• 400m crank offset ground .125" for total stroke of 4.125"
• tw heads port matched on intake, ported on exhaust
• John Free straightened GT40 351W lower (epoxied because it broke through the metal on almost every port)
• Cobra (GT40) upper port matched and blended
• BBK 70mm tb or 70mm Edelbrock
• Motorcraft 70mm maf
• 30# injectors
• Duff long tube headers
• Solid lifter cam.
• A9P EEC controller

I was told that the EEC wouldn’t be able to handle my engine modifications, but it is running great. It adapted perfectly, seamlessly, so much so that I now have a cooling problem that I've never had to deal with. It runs too cold. 150 to 160 degrees, on a 95 degree day -- idling. All my other motors would have climbed to at least 240 under the same conditions. And I'm getting 13 to 14mpg, with the 6.5" of lift and 36" Super Swampers (bias ply) and a lead foot. It works great. And if it can work great with a 7.0l motor, a 5.8l, normally aspirated and not too hopped up one should be a piece of cake! The A9P EEC is totally stock – no programming done to it – and the fuel pressure is set to the stock value (the computer quickly adapts for any changes that are made anyway).

As far as injectors, I didn't go wrong by going with Ford MAF. I used the 70mm calibrated for 30lb injectors, and it's idling perfectly for as big a cam as I'm running. No surging, just a lumpy idle that jumps from 650 to 800 beat by beat. It's amazing how well this is running; it surpassed all my expectations. It idles through mud bogs at 800 rpms at 10k feet, jumps to 6k rpm in a heartbeat, starts up cold just fine, and has great manners.

There was one real problem with vapor locking; but that was cured by better routing and some insulating. The amount of under hood heat given off by the aluminum heads and the headers has been tremendous -- so much so that I can feel it radiate through the Rhino on my feet when I rev it as distinctive heat waves.

It runs better with the EGR installed and that is a contributing factor in the excellent 14 mpg I get, even while doing 85-90mph on the highway. Can't complain about that with the motor I’m running!

It's rich at idle, but it clears up once past about 900 rpm. It's a rough, lumpity idle, but runs great and lugs well.

The biggest difficulty I had was designing the fuel system and all the bugs still aren’t worked out. The research was also a lot of trouble. I went to Ford and they simply told me it'd never work. That was an open challenge, so I did it and brought it back to them. It runs great! No bucking or funny drive-ability problems and the stock computer handles it well.

(Bob Nell’s instructions from converting an SD Mustang to a MAF/SEFI setup is available at several places on the internet as well as in the EEC-IV technical document compiled by the author – also available on the internet.)

To convert SD trucks with E4OD/AODE transmissions to MAF, most people use the California 5.8 MAF/E4OD (F5TF-12A650-BYA). It is obtainable through any Ford dealer (Pro-M, Kenne Bell, LCA, Downs Ford). Mike Wesley said: "I use the F5TF-12A650-HB (95 CA 5.0 MAF/E4OD) on a 750+ HP daily driver 415 stroker Lightning with a Vortech S trim. It is running open loop, has been reprogrammed, drives like stock, gets 17 MPG and will run low 10's at 130+ in the 1/4 mile and A/C and cruise work great." Both of these EEC's are set to use 4.10 gears. If a smaller ratio is used, say 3.55, you could use the F5TF-12A650-GB. There are probably 15-20 EEC's available to convert a SD (later model) to MAF.

Early SD trucks with AOD require moving and adding a number of wires to make the Mustang EEC work (Ford MotorSport sells this kit) and you might not like the results if you're not able to re-calibrate the EEC. (The Pro-M 'low cost' kit also requires calibration whereas the Kenne Bell, LCA and Downs Ford kits come calibrated). For example, the engine shuts down at 85 MPH and the shifting is fairly sloppy and too early (at least on a Lightning). All Ford EECs shift poorly -- except for the Lightning, which is only slightly firmer.

To use the Mustang EEC on a truck with an E4OD/AODE, you need to run two EECs in parallel. The Mustang EEC runs the engine and the existing truck EEC controls the transmission. Pro-M sells a kit like this.

I converted from speed density, bank fired EFI to MAF/SEFI because of the motor I built. My speed density system wouldn't work with the motor modifications which basically just freed my motor up so it would breath better. The intake plenum and heads were ported & polished and a 3-angle valve job was done. Both the intake and exhaust were port matched to the heads. 3" free flow pipes for the exhaust and the block was bored .30" over. The speed density computer ran the motor lean so I went with a '93 mustang MAF computer. The fuel injector harness was changed and all the leads were removed from the 60 pin connector (for the CPU) and matched up to the mustang computer (with a lot of help from the factory Ford manual). Dual 4 wire HEGOs were installed along with a 75mm MAF meter. The MAP sensor was changed to a BAP sensor, and that was that. I also had to do some modifications to my intake system and I was ready to go. It works great with my Paxton S.C. as I'm putting out over 500 hp. It took me awhile to troubleshoot the system and get everything straightened out (read the error codes, look them up, scratch my head, change something and start again).

I didn't switch throttle bodies. The Lightning pickups use a "Y" pipe to go from a single intake hose to the throttle body, so I have a Mustang air cleaner top, MAF meter, and then the Y adapter. I cut the dual hoses down and clamped them to the 'Y' pipe. (at least that’s the way it was initially -- now I have a Paxton in that lineup).

A '95 Califrutti Bronco computer was used to control the E4OD transmission. It’s MAF and also controls the E4OD but it’s not as aggressive as the Mustang computers. So, I had a chip burned to copy the Mustang computer’s aggressive spark curve and fuel/air mixture, while still being able to control the E4OD.

I think the EGR should be connected to a "timed" vacuum port. That is a vacuum port that has its source above the throttle plates of the carb so that there is no vacuum present at idle.

As the throttle opens, the vacuum works its way up in the venturi and, wala, vacuum becomes available at the "timed" port, and the EGR starts to oscillate. (Now, if you’re running headers and a "back-pressure transducer" type EGR, you’re probably going to need to do some more tuning of the EGR flow. I'm running headers into 2.5" collectors, 2.5" pipes and a low restriction muffler in each bank. (What's a back-pressure transducer type EGR?) Another writer says he’s running the stock EGR for a '93 mustang Cobra setup and has massive amounts of power available (even at the altitudes above 13K') so losing a small bit to EGR is not a problem. I'm more worried with it running right. I don't like the idea of leaning out at part throttle. (Is the EGR valve supposed to oscillate or simply open and close due to vacuum?)

The timed vacuum port line should also go through a TVS so that the EGR doesn't function during engine warm-up. (What-the-heck is a TVS?)

I want EGR for two reasons; the computer expects to see it and will lean out the mixture dangerously at part throttle without it, and I like the fuel economy it affords (with 423ci and a big tired Bronco, mpg is a Holy Grail of sorts).

If you opt for convenience or looks, you will regret not having the EGR functional. If it isn't hooked up and functioning properly, the car will run poorly, you’ll have bad MPGs and you won't be happy with the throttle response at all. You would've been WAY better off with an Edelbrock carb on a dual plane, than fuel injection.