360 Questions.. pardon my ignorance.
Came here because I have pretty much the same truck, same setup. '74 D200 truck, 360, Holley 2210. My setup runs PERFECT, so I wanted to let you in on where I ended up with it, starting with square transfer slots:
10 degrees initial, limited to 33 all in
Ported vacuum advance
mix screws 2.25 turns out.
This equals a 700rpm idle.
For what it's worth.