Kog, wasn't saying disconnect the vacuum advance and leave it at that, just commenting that sometimes vacuum advance on RB engines may at times advance too fast and cause pinging if it advances too quickly.
Cris, you need to get ahold of a referee or go online to see what your smog laws are. Some states will allow a change of carb, others will not. Some will allow a tail sniff that sniffs cleaner than limits set for a specific vehicle or engine and could care less what is under the hood, and here in California, numbers on EGR, catalytic converters, vacuum hose routing, you name it, if it isn't CAFE approved, you fail. In other words, find out what you can and cannot have different than stock before buying or changing a whole lot of stuff, it's the safe way to do it.
The Six pack single 350cfm 2bbl carb would not go onto your 440 by itself without a 4bbl to 2bbl adapter plate, to which there was not a single RB ( 413/426 wedge/440 that ever had a 2bbl intake manifold), it is just too small a carb to run that large a vehicle to boot.
See if the smog rules allow the Holley carb, which they might.