Ford’s mass air computer system is pure genius. It is an adaptable EFI system for a V-8 that was offered on a factory vehicle. And, this system can be obtained at almost any junkyard. Ford’s mass air computer system actually senses how much air is entering the motor. The computer uses this information along with input from the rest of the sensors and makes all the adjustments for the engine to run optimally. The computer does this on it’s own! There is no need to program the computer and create an air/fuel table for the computer to reference like the aftermarket programmable computer systems. Ford’s EFI makes 40,000 calculations a second to ensure that the engine runs optimally at all times. The only things that you need to do are: 1.) Set the engine’s timing (done by turning the distributor) 2.) Set the fuel pressure (done with an aftermarket adjustable fuel pressure regulator) 3.) Adjust the throttle position sensor (done with a digital volt meter and a phillips-skrew driver in less than 5 minutes). That’s it. Getting all the sensors in place and wiring the engine compartment to look neat took more effort.
Now, for the big-block guys that are wondering, “hey, will this work for me.” I am sure that it can work. As long as the fuel system is big enough to support your horse power level (injector size, fuel pump, fuel lines, fuel rails) AND the air inlet is big enough to allow enough CFM for your engine’s horse power level (mass air sensor, throttle body), the system should work. Ford's EFI can control 42lb and 50lb fuel injectors. As long as the mass air sensor is calibrated to the same injector size, the computer can control it. The after market makes a bunch of different mass air sensors and throttle bodies for high horse power Mustang guys. These big components and injectors should be adequate to supply enough fuel and air to a modified 440.
For example, the stock EFI 5.0 Mustang engine only made 225 horse power, so stock 19lb fuel injectors, a 60mm throttle body and a 55mm mass air sensor was adequate. My Mopar 360 is a 5.9 and is modified (oh, yeah!!!!) to make about 370 horse power. Some stock Mustang components would be too small. I got 30lb injectors, a 70mm throttle body and a 73mm mass air sensor to satisfy my 360's needs for fuel and air.
The only restriction worth mentioning is that the computer's rev limit is 6,250 rpm’s. To rev above this rpm would require one of many aftermarket devices that are made for Mustang guys. Hmmmmm, I know that 340's like to rev.
