[T77911S]

I played around with the mixture on my 77s a LOT before I got an LM2. in the end what I was doing before I had the LM worked after I had the LM.

I would set the mixture richer and richer until one of things happened (at idle).
either it would surge after idling for bit or when I let off the gas the RPM would drop below idle then come back up. once I reached one of these to symptoms I was too rich and then I would back it off until it did not do either one. I don't remember the exact AFR at idle.

another thing you can do is set your steady cruise AFR to 14.5 up to 15 and see where you like it.

this is a good way to get in touch with your car and learn it.

another approach is if it runs fine where it is don't mess with it.
hot plugs can also make a rich mixture look ok.