My new setup is in the sig. As you can see, I have the adjustable mechanical advance billet distributor from MSD. It is currently on the weakest possible timing curve and the lowest stop bushing. Which timing curve would be a good place to start? Also, what do you guys typically run for base idle timing? Thanks in advance.

I’m running pretty close to what you have...
Comp XE284
Edelbrock 64cc rpm head
Victor Jr.
MSD Distributor, 6AL, Blaster 2, 8.5's, Champion 71 w/.050gap
Holley 830 DP

The funny thing is, I've been testing in tuning today to find optimal curve. I’m going to tune more tomorrow. (More carb though)

Right now I have the black bushings for 18° total mech.
Base 20°; Total 38°; & NO vacuum adv.
Springs: silver lite & silver heavy (<- testing these springs tomorrow, had blue & lite silver)

I know 20° base is a lot, but she idles better & has a little bit crisper throttle response than my previous setting of: Base 15; Total 36 - blue stop.

I'm still messing with the springs a little, cause on my last test(blue - lite silver) she was popping a little around 2000rpms or so. I'm thinking a slower slope might help.

To answer you’re question: TEST & TUNE. It's a lot of work, but it pays off. Remember to change ONE thing at time. You know - don't start changing squirters, jets, PV & adv springs on one stop...

There's a long drawn out way of doing the perfect curve, which basically involves the use of a HP meter. Test & tune – test & tune.
It's all laid out in a book called optimizing your ignition by Jacobs.
You advance it till it pings, and back it off a degree or two. You do this every 500 to 1000rpm increments from idle to red line. You chart the results, and pick the closest spring curve to match.

Ron