Just an update...
Purchased and installed the Coolcarb kit with riser and did the installation on my 440/ Holley 670 Monday. Went on smoothly and so far- running much better. I've also topped off the tank with REC90, which I always try to run- when I'm in the area that sells it.
This should definitely help with Ethanol based fuel though!
Also adjusted the idle. Got it idling at about 900-950, which seems to have eliminated the "clunks" when going into reverse.
Thanks for all the guidance!