Righty, your distributor plate has a series of holes around the outside. They could be there to limit the mechanical advance. If so, set it to ~ 20 degrees. Set initial timing to ~14 degrees.
The outboard carbs could have stuck needle and seat or float [dry bowl syndrome]. And when their throttle plates open up it creates an overly lean condition so that the combustion mixture doesn't fire.
Thanks, I'll be pulling the distributor to have a look. Unfortunately the transmission is also coming out, along with the front end and steering box, so it'll be a while before getting it running again to revisit the timing and carb issues.
One thing I'm definitely going to do is have the throttle shafts removed so I can replace the bushings and ensure free movement. So, while they are off the car, I'll have another look at the needles/seats. I also just realized that I'm running a 5/16" fuel line, whereas from what I understand, the 440-6 came with 3/8" lines (at least from the tank to pump). The good news is I already have the 3/8" line and sender to replace the 5/16", so I'll do that when the transmission is out.