engine harness for $$$

I might be new to the engine electrical management for the Gen III into out A body's, but who and what is the best to use? I believe I have read that the OEM harness that came with the engine has too many circuits that if left unconnected can confuse the computer.

for clarity, I am installing a 6.4 with a Whipple in a 73 Duster. not sure on trans yet, but it will be a stand alone (either an ATI Turbo 400 w/ gear vendor or 833 w/ gear vendor.

interested on any experience from those that have done it.

looking at these three options...so far

a)Mopar stand alone is around $1600 with an unlocked computer / PCM?

b)Holley stand alone harness Holley computer

c) OEM harness / computer / PCM that came with the 6.4 Hemi

Any advise or experience would be appreciated.
Thanks,
Denny

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