Using the GM HEI module outside of it's dizzy, just bolted to a fender liner or what-not, had always bugged me from a corrosion potential position. Here on the Coastal Desert I've got to consider such things. One could argue that the GM dizzy isn't a sealed container for the module and I'd agree, but it must be good enough elemental shielding because corrosion isn't a usual complaint.
I'm liking this mod because it provides about the same amount of shielding from the elements as a GM dizzy does, maybe more and it's cool because it's not what people who see it think it is. Years ago (~1988 ) I put a Toyota EI module in one of those old 70's era aftermarket CD Ignition housings and converted the dizzy to the Toyota inductive pick-up too. Looked like an old points driven CD ignition, but was something far better.
As to the TBI wiring, there are many, many wiring diagrams out there suitable for the conversion. The 7747 ECU is the most common and pretty much the only ECU used in swaps. A simple search on the topic will turn up more info than is useful. I have the complete system from a 2.8L GM V6 that I'm working towards installing on my 170ci (2.8L) slant. The biggest issue for me is that I don't want the ECU to have control of the timing at first. So how to send the RPM signal to the ECU w/o also allowing timing control or altering the loom is a dilemma that I've got to solve. Eventually the ECU will have timing control (doing one step at a time), so altering the loom isn't very desirable.
Attached is one such diagram that I found on an I-H site where TBI conversions appear to be quite common.
EDIT: Just now looking at the attached diagram I see the solution to my timing control situation. :)
