All the EEC add-ons I've heard of or seen plug into the card edge connector (service port).
Check out the links below for a programmable system for EEC-IV/EEC-V computers that is fairly reasonably priced. In one of the docs there they have detailed instructions for cleaning and installing a connector.
While the s/w doesn't have direct support for our processors there is 3rd party software that does have some support for Falcons. I have also spoken with other Aussies who have been working with these things so there is some info out there.
<== EEC 4/5 programmable system
<== User/install guide including cleaning instructions
<== 3rd party s/w for programming/decoding EEC 4/5
Of course with the rate of exchange at the moment you may have to sell your car to buy this stuff!