Initial timing settings
While TB and I agree on ported vacuum, the problem is that there are "two schools of thought." Some advocate using FULL vacuum, and IF YOU DO THAT you will need a completely different mechanical curve.
With the way 'we' think, IE ported, timed, no idle vacuum.....
8-12 initial is nowhere near enough.......
you definately want vacuum disconnected at idle
if you go to the Edelbrock site, there are downloads of manuals for the carbs which tell you all you can imagine about them
There has been TONS written on this site about timing.
Here's one
http://www.forabodiesonly.com/mopar/showthread.php?t=158842
and
http://www.forabodiesonly.com/mopar/showthread.php?t=150251
One thing you need to keep in mind. All factory distributors 69 / later are "smog" advance curves, not what you want for performance, and they get worse up into the mid 70's. "Long slow" advance curves as opposed to "fast and short"
This means you either need to replace the smog factory distributor with an adjustable aftermarket one, or else recurve the one you have