EFI considerations for a 1970 383 with very mid cam

When I did my install I used Holley's off the shelf harness 558-328 and the only factory wiring used is the IGN1 and ING2 tired as referenced by Andy. Keep in mind this is for the Gen 1 system with Hyperspark ign box and distributor. It's over priced and kind of oddly laid out but I made it work about as clean as I could with out cutting.

To me, the confusion comes with the 4 install manuals you need to mentally patch together for the install plus the things they don't tell you and you learn from forum searches.

The Gen2 system looks to be a massive clean up and more "system" oriented.

It is a challenge at times, but tuning is so much nicer. No more gas, jets, pump cams, springs, distributor curve chasing and you can data log.