Significance of EEC-IV #s ??

[jb89coupe]

Searched but I couldn't find anything about this... My computer is shot and I need a new one. My car is an 89 5.0 5 speed with an A9L, so I'm looking for another A9L... but what do the other #'s on the computer mean?
For example mine says EEC-IV SFI-MA12 on the top. I've seen others that read EEC-IV SFI-MA12A. I know the MA means mass air, but what's the difference between the MA12 and MA12A? Is the A for an automatic? Airbag??
Also the Ford product number - mine is E9ZF-12A650-A2A. I've found others for sale where the last part varies (-AA, -A2A, -AAS, etc). I called a local Ford dealer about getting a new one, and he said he couldn't cross reference the -A2A, and he wasn't sure what the difference was or if it would even work in my car.

Anyone know what the differences are between these A9L variations? I don't want to get one I can't use.

Thanks.

 

[jrichker]

The A9L is the main identifer. An A9L will work in any 5 speed Mustang from 89-93. It will work in Speed Density cars with the addition of a MAF & wiring mods.

The product number xxxx-12A650 is the main identifer. The -AA or A2A are the minor calibration identifers that have to do with what smog properties are in the computer's program.

See http://fordfuelinjection.com/catchcodes.html for more info