Well that's exactly my point... eliminate the rear harness altogether.
That's what goes to the ESC. There's also a special connector on the
12V Pink wire that runs to the cap that you're refering to, that splits
the pink wire off to ALSO go to the ESC.
So...how about removing that 12V feed to the ESC, and disconnecting the
harness to the HEI.
At that point you'd still have a 5-pin module, and it probably wouldn't
run. HOWEVER, replace the 5-pin module with the 4-pin. As I stated
earlier, the pickup coil connects BETWEEN the module and the ESC. It
uses a 3-pin connector, but only 2 of the wires go to the pick up. The
3rd is straight from the ESC to the module.
Again, regarding the pickup coil ONLY, what is the difference besides
the connector that goes to the module. It's a coil of wire with 2
leads coming off it.
I think converting it to a 4-pin module is easier than we think. I did
a little Googling, and found many performance kits that do this very
thing. Many say specifically that "the knock sensor is not retained",
thus eliminating the ESC from the picture.
To summarize...from what I can tell, the difference between an ESC HEI
and standard HEI is the addition of the ESC and an extra pin on the
module. Remove the ESC altogether, replace the module with a 4-pin
model, and it should work fine....